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migration/qemu-file: remove check on writev_buffer in qemu_put_compression_data
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CommitLineData
9a4ac51f
EH
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 */
1393a485 24#include "qemu/osdep.h"
44f0eadc 25#include <zlib.h>
d49b6836 26#include "qemu/error-report.h"
093c455a 27#include "qemu/iov.h"
6666c96a 28#include "migration.h"
08a0aee1 29#include "qemu-file.h"
9013dca5 30#include "trace.h"
3d661c8a 31#include "qapi/error.h"
093c455a 32
a24939f2
DB
33#define IO_BUF_SIZE 32768
34#define MAX_IOV_SIZE MIN(IOV_MAX, 64)
35
36struct 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
53f09a10 50 DECLARE_BITMAP(may_free, MAX_IOV_SIZE);
a24939f2
DB
51 struct iovec iov[MAX_IOV_SIZE];
52 unsigned int iovcnt;
53
54 int last_error;
3d661c8a 55 Error *last_error_obj;
a24939f2
DB
56};
57
e1a8c9b6
DDAG
58/*
59 * Stop a file from being read/written - not all backing files can do this
60 * typically only sockets can.
61 */
62int qemu_file_shutdown(QEMUFile *f)
63{
64 if (!f->ops->shut_down) {
65 return -ENOSYS;
66 }
3d661c8a 67 return f->ops->shut_down(f->opaque, true, true, NULL);
e1a8c9b6
DDAG
68}
69
adc468e9
DDAG
70/*
71 * Result: QEMUFile* for a 'return path' for comms in the opposite direction
72 * NULL if not available
73 */
74QEMUFile *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
093c455a
EH
82bool 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
093c455a
EH
94QEMUFile *qemu_fopen_ops(void *opaque, const QEMUFileOps *ops)
95{
96 QEMUFile *f;
97
97f3ad35 98 f = g_new0(QEMUFile, 1);
093c455a
EH
99
100 f->opaque = opaque;
101 f->ops = ops;
102 return f;
103}
104
0436e09f
DB
105
106void qemu_file_set_hooks(QEMUFile *f, const QEMUFileHooks *hooks)
107{
108 f->hooks = hooks;
109}
110
093c455a 111/*
3d661c8a 112 * Get last error for stream f with optional Error*
093c455a
EH
113 *
114 * Return negative error value if there has been an error on previous
115 * operations, return 0 if no error happened.
3d661c8a
YK
116 * Optional, it returns Error* in errp, but it may be NULL even if return value
117 * is not 0.
093c455a
EH
118 *
119 */
3d661c8a 120int qemu_file_get_error_obj(QEMUFile *f, Error **errp)
093c455a 121{
3d661c8a
YK
122 if (errp) {
123 *errp = f->last_error_obj ? error_copy(f->last_error_obj) : NULL;
124 }
093c455a
EH
125 return f->last_error;
126}
127
3d661c8a
YK
128/*
129 * Set the last error for stream f with optional Error*
130 */
131void qemu_file_set_error_obj(QEMUFile *f, int ret, Error *err)
093c455a 132{
3d661c8a 133 if (f->last_error == 0 && ret) {
093c455a 134 f->last_error = ret;
3d661c8a
YK
135 error_propagate(&f->last_error_obj, err);
136 } else if (err) {
137 error_report_err(err);
093c455a
EH
138 }
139}
140
3d661c8a
YK
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 */
148int 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 */
156void qemu_file_set_error(QEMUFile *f, int ret)
157{
158 qemu_file_set_error_obj(f, ret, NULL);
159}
160
e68dd365 161bool qemu_file_is_writable(QEMUFile *f)
093c455a 162{
11808bb0 163 return f->ops->writev_buffer;
093c455a
EH
164}
165
53f09a10
PB
166static 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
093c455a
EH
201/**
202 * Flushes QEMUFile buffer
203 *
3b348706
DDAG
204 * This will flush all pending data. If data was only partially flushed, it
205 * will set an error state.
093c455a
EH
206 */
207void qemu_fflush(QEMUFile *f)
208{
209 ssize_t ret = 0;
baf51e77 210 ssize_t expect = 0;
3d661c8a 211 Error *local_error = NULL;
093c455a
EH
212
213 if (!qemu_file_is_writable(f)) {
214 return;
215 }
216
11808bb0
DB
217 if (f->iovcnt > 0) {
218 expect = iov_size(f->iov, f->iovcnt);
3d661c8a
YK
219 ret = f->ops->writev_buffer(f->opaque, f->iov, f->iovcnt, f->pos,
220 &local_error);
53f09a10
PB
221
222 qemu_iovec_release_ram(f);
093c455a 223 }
baf51e77 224
093c455a
EH
225 if (ret >= 0) {
226 f->pos += ret;
227 }
baf51e77
DB
228 /* We expect the QEMUFile write impl to send the full
229 * data set we requested, so sanity check that.
230 */
231 if (ret != expect) {
3d661c8a 232 qemu_file_set_error_obj(f, ret < 0 ? ret : -EIO, local_error);
baf51e77 233 }
093c455a
EH
234 f->buf_index = 0;
235 f->iovcnt = 0;
093c455a
EH
236}
237
238void ram_control_before_iterate(QEMUFile *f, uint64_t flags)
239{
240 int ret = 0;
241
0436e09f
DB
242 if (f->hooks && f->hooks->before_ram_iterate) {
243 ret = f->hooks->before_ram_iterate(f, f->opaque, flags, NULL);
093c455a
EH
244 if (ret < 0) {
245 qemu_file_set_error(f, ret);
246 }
247 }
248}
249
250void ram_control_after_iterate(QEMUFile *f, uint64_t flags)
251{
252 int ret = 0;
253
0436e09f
DB
254 if (f->hooks && f->hooks->after_ram_iterate) {
255 ret = f->hooks->after_ram_iterate(f, f->opaque, flags, NULL);
093c455a
EH
256 if (ret < 0) {
257 qemu_file_set_error(f, ret);
258 }
259 }
260}
261
632e3a5c 262void ram_control_load_hook(QEMUFile *f, uint64_t flags, void *data)
093c455a
EH
263{
264 int ret = -EINVAL;
265
0436e09f
DB
266 if (f->hooks && f->hooks->hook_ram_load) {
267 ret = f->hooks->hook_ram_load(f, f->opaque, flags, data);
093c455a
EH
268 if (ret < 0) {
269 qemu_file_set_error(f, ret);
270 }
271 } else {
632e3a5c
DDAG
272 /*
273 * Hook is a hook specifically requested by the source sending a flag
274 * that expects there to be a hook on the destination.
275 */
276 if (flags == RAM_CONTROL_HOOK) {
277 qemu_file_set_error(f, ret);
278 }
093c455a
EH
279 }
280}
281
282size_t ram_control_save_page(QEMUFile *f, ram_addr_t block_offset,
6e1dea46
JQ
283 ram_addr_t offset, size_t size,
284 uint64_t *bytes_sent)
093c455a 285{
0436e09f
DB
286 if (f->hooks && f->hooks->save_page) {
287 int ret = f->hooks->save_page(f, f->opaque, block_offset,
288 offset, size, bytes_sent);
ccb7e1b5
LC
289 if (ret != RAM_SAVE_CONTROL_NOT_SUPP) {
290 f->bytes_xfer += size;
291 }
292
293 if (ret != RAM_SAVE_CONTROL_DELAYED &&
294 ret != RAM_SAVE_CONTROL_NOT_SUPP) {
093c455a
EH
295 if (bytes_sent && *bytes_sent > 0) {
296 qemu_update_position(f, *bytes_sent);
297 } else if (ret < 0) {
298 qemu_file_set_error(f, ret);
299 }
300 }
301
302 return ret;
303 }
304
305 return RAM_SAVE_CONTROL_NOT_SUPP;
306}
307
548f52ea
DDAG
308/*
309 * Attempt to fill the buffer from the underlying file
310 * Returns the number of bytes read, or negative value for an error.
311 *
312 * Note that it can return a partially full buffer even in a not error/not EOF
313 * case if the underlying file descriptor gives a short read, and that can
314 * happen even on a blocking fd.
315 */
316static ssize_t qemu_fill_buffer(QEMUFile *f)
093c455a
EH
317{
318 int len;
319 int pending;
3d661c8a 320 Error *local_error = NULL;
093c455a
EH
321
322 assert(!qemu_file_is_writable(f));
323
324 pending = f->buf_size - f->buf_index;
325 if (pending > 0) {
326 memmove(f->buf, f->buf + f->buf_index, pending);
327 }
328 f->buf_index = 0;
329 f->buf_size = pending;
330
331 len = f->ops->get_buffer(f->opaque, f->buf + pending, f->pos,
3d661c8a 332 IO_BUF_SIZE - pending, &local_error);
093c455a
EH
333 if (len > 0) {
334 f->buf_size += len;
335 f->pos += len;
336 } else if (len == 0) {
3d661c8a 337 qemu_file_set_error_obj(f, -EIO, local_error);
093c455a 338 } else if (len != -EAGAIN) {
3d661c8a
YK
339 qemu_file_set_error_obj(f, len, local_error);
340 } else {
341 error_free(local_error);
093c455a 342 }
548f52ea
DDAG
343
344 return len;
093c455a
EH
345}
346
093c455a
EH
347void qemu_update_position(QEMUFile *f, size_t size)
348{
349 f->pos += size;
350}
351
352/** Closes the file
353 *
354 * Returns negative error value if any error happened on previous operations or
355 * while closing the file. Returns 0 or positive number on success.
356 *
357 * The meaning of return value on success depends on the specific backend
358 * being used.
359 */
360int qemu_fclose(QEMUFile *f)
361{
362 int ret;
363 qemu_fflush(f);
364 ret = qemu_file_get_error(f);
365
366 if (f->ops->close) {
3d661c8a 367 int ret2 = f->ops->close(f->opaque, NULL);
093c455a
EH
368 if (ret >= 0) {
369 ret = ret2;
370 }
371 }
372 /* If any error was spotted before closing, we should report it
373 * instead of the close() return value.
374 */
375 if (f->last_error) {
376 ret = f->last_error;
377 }
3d661c8a 378 error_free(f->last_error_obj);
093c455a 379 g_free(f);
9013dca5 380 trace_qemu_file_fclose();
093c455a
EH
381 return ret;
382}
383
53f09a10
PB
384static void add_to_iovec(QEMUFile *f, const uint8_t *buf, size_t size,
385 bool may_free)
093c455a
EH
386{
387 /* check for adjacent buffer and coalesce them */
388 if (f->iovcnt > 0 && buf == f->iov[f->iovcnt - 1].iov_base +
53f09a10
PB
389 f->iov[f->iovcnt - 1].iov_len &&
390 may_free == test_bit(f->iovcnt - 1, f->may_free))
391 {
093c455a
EH
392 f->iov[f->iovcnt - 1].iov_len += size;
393 } else {
53f09a10
PB
394 if (may_free) {
395 set_bit(f->iovcnt, f->may_free);
396 }
093c455a
EH
397 f->iov[f->iovcnt].iov_base = (uint8_t *)buf;
398 f->iov[f->iovcnt++].iov_len = size;
399 }
400
401 if (f->iovcnt >= MAX_IOV_SIZE) {
402 qemu_fflush(f);
403 }
404}
405
53f09a10
PB
406void qemu_put_buffer_async(QEMUFile *f, const uint8_t *buf, size_t size,
407 bool may_free)
093c455a 408{
093c455a
EH
409 if (f->last_error) {
410 return;
411 }
412
413 f->bytes_xfer += size;
53f09a10 414 add_to_iovec(f, buf, size, may_free);
093c455a
EH
415}
416
56f3835f 417void qemu_put_buffer(QEMUFile *f, const uint8_t *buf, size_t size)
093c455a 418{
56f3835f 419 size_t l;
093c455a
EH
420
421 if (f->last_error) {
422 return;
423 }
424
425 while (size > 0) {
426 l = IO_BUF_SIZE - f->buf_index;
427 if (l > size) {
428 l = size;
429 }
430 memcpy(f->buf + f->buf_index, buf, l);
431 f->bytes_xfer += l;
53f09a10 432 add_to_iovec(f, f->buf + f->buf_index, l, false);
093c455a
EH
433 f->buf_index += l;
434 if (f->buf_index == IO_BUF_SIZE) {
435 qemu_fflush(f);
436 }
437 if (qemu_file_get_error(f)) {
438 break;
439 }
440 buf += l;
441 size -= l;
442 }
443}
444
445void qemu_put_byte(QEMUFile *f, int v)
446{
447 if (f->last_error) {
448 return;
449 }
450
451 f->buf[f->buf_index] = v;
452 f->bytes_xfer++;
53f09a10 453 add_to_iovec(f, f->buf + f->buf_index, 1, false);
093c455a
EH
454 f->buf_index++;
455 if (f->buf_index == IO_BUF_SIZE) {
456 qemu_fflush(f);
457 }
458}
459
460void qemu_file_skip(QEMUFile *f, int size)
461{
462 if (f->buf_index + size <= f->buf_size) {
463 f->buf_index += size;
464 }
465}
466
548f52ea 467/*
7c1e52ba
DDAG
468 * Read 'size' bytes from file (at 'offset') without moving the
469 * pointer and set 'buf' to point to that data.
548f52ea
DDAG
470 *
471 * It will return size bytes unless there was an error, in which case it will
472 * return as many as it managed to read (assuming blocking fd's which
473 * all current QEMUFile are)
474 */
56f3835f 475size_t qemu_peek_buffer(QEMUFile *f, uint8_t **buf, size_t size, size_t offset)
093c455a 476{
56f3835f
DDAG
477 ssize_t pending;
478 size_t index;
093c455a
EH
479
480 assert(!qemu_file_is_writable(f));
548f52ea
DDAG
481 assert(offset < IO_BUF_SIZE);
482 assert(size <= IO_BUF_SIZE - offset);
093c455a 483
548f52ea 484 /* The 1st byte to read from */
093c455a 485 index = f->buf_index + offset;
548f52ea 486 /* The number of available bytes starting at index */
093c455a 487 pending = f->buf_size - index;
548f52ea
DDAG
488
489 /*
490 * qemu_fill_buffer might return just a few bytes, even when there isn't
491 * an error, so loop collecting them until we get enough.
492 */
493 while (pending < size) {
494 int received = qemu_fill_buffer(f);
495
496 if (received <= 0) {
497 break;
498 }
499
093c455a
EH
500 index = f->buf_index + offset;
501 pending = f->buf_size - index;
502 }
503
504 if (pending <= 0) {
505 return 0;
506 }
507 if (size > pending) {
508 size = pending;
509 }
510
7c1e52ba 511 *buf = f->buf + index;
093c455a
EH
512 return size;
513}
514
548f52ea
DDAG
515/*
516 * Read 'size' bytes of data from the file into buf.
517 * 'size' can be larger than the internal buffer.
518 *
519 * It will return size bytes unless there was an error, in which case it will
520 * return as many as it managed to read (assuming blocking fd's which
521 * all current QEMUFile are)
522 */
56f3835f 523size_t qemu_get_buffer(QEMUFile *f, uint8_t *buf, size_t size)
093c455a 524{
56f3835f
DDAG
525 size_t pending = size;
526 size_t done = 0;
093c455a
EH
527
528 while (pending > 0) {
56f3835f 529 size_t res;
7c1e52ba 530 uint8_t *src;
093c455a 531
7c1e52ba 532 res = qemu_peek_buffer(f, &src, MIN(pending, IO_BUF_SIZE), 0);
093c455a
EH
533 if (res == 0) {
534 return done;
535 }
7c1e52ba 536 memcpy(buf, src, res);
093c455a
EH
537 qemu_file_skip(f, res);
538 buf += res;
539 pending -= res;
540 done += res;
541 }
542 return done;
543}
544
9504fb51
DDAG
545/*
546 * Read 'size' bytes of data from the file.
547 * 'size' can be larger than the internal buffer.
548 *
549 * The data:
550 * may be held on an internal buffer (in which case *buf is updated
551 * to point to it) that is valid until the next qemu_file operation.
552 * OR
553 * will be copied to the *buf that was passed in.
554 *
555 * The code tries to avoid the copy if possible.
556 *
557 * It will return size bytes unless there was an error, in which case it will
558 * return as many as it managed to read (assuming blocking fd's which
559 * all current QEMUFile are)
560 *
561 * Note: Since **buf may get changed, the caller should take care to
562 * keep a pointer to the original buffer if it needs to deallocate it.
563 */
564size_t qemu_get_buffer_in_place(QEMUFile *f, uint8_t **buf, size_t size)
565{
566 if (size < IO_BUF_SIZE) {
567 size_t res;
568 uint8_t *src;
569
570 res = qemu_peek_buffer(f, &src, size, 0);
571
572 if (res == size) {
573 qemu_file_skip(f, res);
574 *buf = src;
575 return res;
576 }
577 }
578
579 return qemu_get_buffer(f, *buf, size);
580}
581
548f52ea
DDAG
582/*
583 * Peeks a single byte from the buffer; this isn't guaranteed to work if
584 * offset leaves a gap after the previous read/peeked data.
585 */
093c455a
EH
586int qemu_peek_byte(QEMUFile *f, int offset)
587{
588 int index = f->buf_index + offset;
589
590 assert(!qemu_file_is_writable(f));
548f52ea 591 assert(offset < IO_BUF_SIZE);
093c455a
EH
592
593 if (index >= f->buf_size) {
594 qemu_fill_buffer(f);
595 index = f->buf_index + offset;
596 if (index >= f->buf_size) {
597 return 0;
598 }
599 }
600 return f->buf[index];
601}
602
603int qemu_get_byte(QEMUFile *f)
604{
605 int result;
606
607 result = qemu_peek_byte(f, 0);
608 qemu_file_skip(f, 1);
609 return result;
610}
611
97221400
AG
612int64_t qemu_ftell_fast(QEMUFile *f)
613{
614 int64_t ret = f->pos;
615 int i;
616
11808bb0
DB
617 for (i = 0; i < f->iovcnt; i++) {
618 ret += f->iov[i].iov_len;
97221400
AG
619 }
620
621 return ret;
622}
623
093c455a
EH
624int64_t qemu_ftell(QEMUFile *f)
625{
626 qemu_fflush(f);
627 return f->pos;
628}
629
630int qemu_file_rate_limit(QEMUFile *f)
631{
632 if (qemu_file_get_error(f)) {
633 return 1;
634 }
635 if (f->xfer_limit > 0 && f->bytes_xfer > f->xfer_limit) {
636 return 1;
637 }
638 return 0;
639}
640
641int64_t qemu_file_get_rate_limit(QEMUFile *f)
642{
643 return f->xfer_limit;
644}
645
646void qemu_file_set_rate_limit(QEMUFile *f, int64_t limit)
647{
648 f->xfer_limit = limit;
649}
650
651void qemu_file_reset_rate_limit(QEMUFile *f)
652{
653 f->bytes_xfer = 0;
654}
655
5d7d2558
IR
656void qemu_file_update_transfer(QEMUFile *f, int64_t len)
657{
658 f->bytes_xfer += len;
659}
660
093c455a
EH
661void qemu_put_be16(QEMUFile *f, unsigned int v)
662{
663 qemu_put_byte(f, v >> 8);
664 qemu_put_byte(f, v);
665}
666
667void qemu_put_be32(QEMUFile *f, unsigned int v)
668{
669 qemu_put_byte(f, v >> 24);
670 qemu_put_byte(f, v >> 16);
671 qemu_put_byte(f, v >> 8);
672 qemu_put_byte(f, v);
673}
674
675void qemu_put_be64(QEMUFile *f, uint64_t v)
676{
677 qemu_put_be32(f, v >> 32);
678 qemu_put_be32(f, v);
679}
680
681unsigned int qemu_get_be16(QEMUFile *f)
682{
683 unsigned int v;
684 v = qemu_get_byte(f) << 8;
685 v |= qemu_get_byte(f);
686 return v;
687}
688
689unsigned int qemu_get_be32(QEMUFile *f)
690{
691 unsigned int v;
90d6a673 692 v = (unsigned int)qemu_get_byte(f) << 24;
093c455a
EH
693 v |= qemu_get_byte(f) << 16;
694 v |= qemu_get_byte(f) << 8;
695 v |= qemu_get_byte(f);
696 return v;
697}
698
699uint64_t qemu_get_be64(QEMUFile *f)
700{
701 uint64_t v;
702 v = (uint64_t)qemu_get_be32(f) << 32;
703 v |= qemu_get_be32(f);
704 return v;
705}
44f0eadc 706
dcaf446e
XG
707/* return the size after compression, or negative value on error */
708static int qemu_compress_data(z_stream *stream, uint8_t *dest, size_t dest_len,
709 const uint8_t *source, size_t source_len)
710{
711 int err;
712
713 err = deflateReset(stream);
714 if (err != Z_OK) {
715 return -1;
716 }
717
718 stream->avail_in = source_len;
719 stream->next_in = (uint8_t *)source;
720 stream->avail_out = dest_len;
721 stream->next_out = dest;
722
723 err = deflate(stream, Z_FINISH);
724 if (err != Z_STREAM_END) {
725 return -1;
726 }
727
728 return stream->next_out - dest;
729}
730
731/* Compress size bytes of data start at p and store the compressed
732 * data to the buffer of f.
b3be2896
LL
733 *
734 * When f is not writable, return -1 if f has no space to save the
735 * compressed data.
736 * When f is wirtable and it has no space to save the compressed data,
737 * do fflush first, if f still has no space to save the compressed
738 * data, return -1.
44f0eadc 739 */
dcaf446e
XG
740ssize_t qemu_put_compression_data(QEMUFile *f, z_stream *stream,
741 const uint8_t *p, size_t size)
44f0eadc
LL
742{
743 ssize_t blen = IO_BUF_SIZE - f->buf_index - sizeof(int32_t);
744
745 if (blen < compressBound(size)) {
b3be2896
LL
746 if (!qemu_file_is_writable(f)) {
747 return -1;
748 }
749 qemu_fflush(f);
750 blen = IO_BUF_SIZE - sizeof(int32_t);
751 if (blen < compressBound(size)) {
752 return -1;
753 }
44f0eadc 754 }
dcaf446e
XG
755
756 blen = qemu_compress_data(stream, f->buf + f->buf_index + sizeof(int32_t),
757 blen, p, size);
758 if (blen < 0) {
34ab9e97 759 return -1;
44f0eadc 760 }
34ab9e97 761
44f0eadc 762 qemu_put_be32(f, blen);
89fe04b4 763 add_to_iovec(f, f->buf + f->buf_index, blen, false);
44f0eadc 764 f->buf_index += blen;
b3be2896
LL
765 if (f->buf_index == IO_BUF_SIZE) {
766 qemu_fflush(f);
767 }
44f0eadc
LL
768 return blen + sizeof(int32_t);
769}
770
771/* Put the data in the buffer of f_src to the buffer of f_des, and
772 * then reset the buf_index of f_src to 0.
773 */
774
775int qemu_put_qemu_file(QEMUFile *f_des, QEMUFile *f_src)
776{
777 int len = 0;
778
779 if (f_src->buf_index > 0) {
780 len = f_src->buf_index;
781 qemu_put_buffer(f_des, f_src->buf, f_src->buf_index);
782 f_src->buf_index = 0;
787d134f 783 f_src->iovcnt = 0;
44f0eadc
LL
784 }
785 return len;
786}
b3af1bc9
DDAG
787
788/*
789 * Get a string whose length is determined by a single preceding byte
790 * A preallocated 256 byte buffer must be passed in.
791 * Returns: len on success and a 0 terminated string in the buffer
792 * else 0
793 * (Note a 0 length string will return 0 either way)
794 */
795size_t qemu_get_counted_string(QEMUFile *f, char buf[256])
796{
797 size_t len = qemu_get_byte(f);
798 size_t res = qemu_get_buffer(f, (uint8_t *)buf, len);
799
800 buf[res] = 0;
801
802 return res == len ? res : 0;
803}
a800cd5c 804
f0d64cb7
VSO
805/*
806 * Put a string with one preceding byte containing its length. The length of
807 * the string should be less than 256.
808 */
809void qemu_put_counted_string(QEMUFile *f, const char *str)
810{
811 size_t len = strlen(str);
812
813 assert(len < 256);
814 qemu_put_byte(f, len);
815 qemu_put_buffer(f, (const uint8_t *)str, len);
816}
817
a800cd5c
DDAG
818/*
819 * Set the blocking state of the QEMUFile.
820 * Note: On some transports the OS only keeps a single blocking state for
821 * both directions, and thus changing the blocking on the main
822 * QEMUFile can also affect the return path.
823 */
824void qemu_file_set_blocking(QEMUFile *f, bool block)
825{
06ad5135 826 if (f->ops->set_blocking) {
3d661c8a 827 f->ops->set_blocking(f->opaque, block, NULL);
a800cd5c
DDAG
828 }
829}