root / nbd.c @ e25ceb76
History | View | Annotate | Download (24.4 kB)
1 |
/*
|
---|---|
2 |
* Copyright (C) 2005 Anthony Liguori <anthony@codemonkey.ws>
|
3 |
*
|
4 |
* Network Block Device
|
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; under version 2 of the License.
|
9 |
*
|
10 |
* This program is distributed in the hope that it will be useful,
|
11 |
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
12 |
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
13 |
* GNU General Public License for more details.
|
14 |
*
|
15 |
* You should have received a copy of the GNU General Public License
|
16 |
* along with this program; if not, see <http://www.gnu.org/licenses/>.
|
17 |
*/
|
18 |
|
19 |
#include "nbd.h" |
20 |
#include "block.h" |
21 |
|
22 |
#include "qemu-coroutine.h" |
23 |
|
24 |
#include <errno.h> |
25 |
#include <string.h> |
26 |
#ifndef _WIN32
|
27 |
#include <sys/ioctl.h> |
28 |
#endif
|
29 |
#if defined(__sun__) || defined(__HAIKU__)
|
30 |
#include <sys/ioccom.h> |
31 |
#endif
|
32 |
#include <ctype.h> |
33 |
#include <inttypes.h> |
34 |
|
35 |
#ifdef __linux__
|
36 |
#include <linux/fs.h> |
37 |
#endif
|
38 |
|
39 |
#include "qemu_socket.h" |
40 |
#include "qemu-queue.h" |
41 |
|
42 |
//#define DEBUG_NBD
|
43 |
|
44 |
#ifdef DEBUG_NBD
|
45 |
#define TRACE(msg, ...) do { \ |
46 |
LOG(msg, ## __VA_ARGS__); \ |
47 |
} while(0) |
48 |
#else
|
49 |
#define TRACE(msg, ...) \
|
50 |
do { } while (0) |
51 |
#endif
|
52 |
|
53 |
#define LOG(msg, ...) do { \ |
54 |
fprintf(stderr, "%s:%s():L%d: " msg "\n", \ |
55 |
__FILE__, __FUNCTION__, __LINE__, ## __VA_ARGS__); \ |
56 |
} while(0) |
57 |
|
58 |
/* This is all part of the "official" NBD API */
|
59 |
|
60 |
#define NBD_REPLY_SIZE (4 + 4 + 8) |
61 |
#define NBD_REQUEST_MAGIC 0x25609513 |
62 |
#define NBD_REPLY_MAGIC 0x67446698 |
63 |
|
64 |
#define NBD_SET_SOCK _IO(0xab, 0) |
65 |
#define NBD_SET_BLKSIZE _IO(0xab, 1) |
66 |
#define NBD_SET_SIZE _IO(0xab, 2) |
67 |
#define NBD_DO_IT _IO(0xab, 3) |
68 |
#define NBD_CLEAR_SOCK _IO(0xab, 4) |
69 |
#define NBD_CLEAR_QUE _IO(0xab, 5) |
70 |
#define NBD_PRINT_DEBUG _IO(0xab, 6) |
71 |
#define NBD_SET_SIZE_BLOCKS _IO(0xab, 7) |
72 |
#define NBD_DISCONNECT _IO(0xab, 8) |
73 |
#define NBD_SET_TIMEOUT _IO(0xab, 9) |
74 |
#define NBD_SET_FLAGS _IO(0xab, 10) |
75 |
|
76 |
#define NBD_OPT_EXPORT_NAME (1 << 0) |
77 |
|
78 |
/* That's all folks */
|
79 |
|
80 |
ssize_t nbd_wr_sync(int fd, void *buffer, size_t size, bool do_read) |
81 |
{ |
82 |
size_t offset = 0;
|
83 |
int err;
|
84 |
|
85 |
if (qemu_in_coroutine()) {
|
86 |
if (do_read) {
|
87 |
return qemu_co_recv(fd, buffer, size);
|
88 |
} else {
|
89 |
return qemu_co_send(fd, buffer, size);
|
90 |
} |
91 |
} |
92 |
|
93 |
while (offset < size) {
|
94 |
ssize_t len; |
95 |
|
96 |
if (do_read) {
|
97 |
len = qemu_recv(fd, buffer + offset, size - offset, 0);
|
98 |
} else {
|
99 |
len = send(fd, buffer + offset, size - offset, 0);
|
100 |
} |
101 |
|
102 |
if (len < 0) { |
103 |
err = socket_error(); |
104 |
|
105 |
/* recoverable error */
|
106 |
if (err == EINTR || (offset > 0 && err == EAGAIN)) { |
107 |
continue;
|
108 |
} |
109 |
|
110 |
/* unrecoverable error */
|
111 |
return -err;
|
112 |
} |
113 |
|
114 |
/* eof */
|
115 |
if (len == 0) { |
116 |
break;
|
117 |
} |
118 |
|
119 |
offset += len; |
120 |
} |
121 |
|
122 |
return offset;
|
123 |
} |
124 |
|
125 |
static ssize_t read_sync(int fd, void *buffer, size_t size) |
126 |
{ |
127 |
/* Sockets are kept in blocking mode in the negotiation phase. After
|
128 |
* that, a non-readable socket simply means that another thread stole
|
129 |
* our request/reply. Synchronization is done with recv_coroutine, so
|
130 |
* that this is coroutine-safe.
|
131 |
*/
|
132 |
return nbd_wr_sync(fd, buffer, size, true); |
133 |
} |
134 |
|
135 |
static ssize_t write_sync(int fd, void *buffer, size_t size) |
136 |
{ |
137 |
int ret;
|
138 |
do {
|
139 |
/* For writes, we do expect the socket to be writable. */
|
140 |
ret = nbd_wr_sync(fd, buffer, size, false);
|
141 |
} while (ret == -EAGAIN);
|
142 |
return ret;
|
143 |
} |
144 |
|
145 |
static void combine_addr(char *buf, size_t len, const char* address, |
146 |
uint16_t port) |
147 |
{ |
148 |
/* If the address-part contains a colon, it's an IPv6 IP so needs [] */
|
149 |
if (strstr(address, ":")) { |
150 |
snprintf(buf, len, "[%s]:%u", address, port);
|
151 |
} else {
|
152 |
snprintf(buf, len, "%s:%u", address, port);
|
153 |
} |
154 |
} |
155 |
|
156 |
int tcp_socket_outgoing(const char *address, uint16_t port) |
157 |
{ |
158 |
char address_and_port[128]; |
159 |
combine_addr(address_and_port, 128, address, port);
|
160 |
return tcp_socket_outgoing_spec(address_and_port);
|
161 |
} |
162 |
|
163 |
int tcp_socket_outgoing_spec(const char *address_and_port) |
164 |
{ |
165 |
return inet_connect(address_and_port, SOCK_STREAM);
|
166 |
} |
167 |
|
168 |
int tcp_socket_incoming(const char *address, uint16_t port) |
169 |
{ |
170 |
char address_and_port[128]; |
171 |
combine_addr(address_and_port, 128, address, port);
|
172 |
return tcp_socket_incoming_spec(address_and_port);
|
173 |
} |
174 |
|
175 |
int tcp_socket_incoming_spec(const char *address_and_port) |
176 |
{ |
177 |
char *ostr = NULL; |
178 |
int olen = 0; |
179 |
return inet_listen(address_and_port, ostr, olen, SOCK_STREAM, 0); |
180 |
} |
181 |
|
182 |
int unix_socket_incoming(const char *path) |
183 |
{ |
184 |
char *ostr = NULL; |
185 |
int olen = 0; |
186 |
|
187 |
return unix_listen(path, ostr, olen);
|
188 |
} |
189 |
|
190 |
int unix_socket_outgoing(const char *path) |
191 |
{ |
192 |
return unix_connect(path);
|
193 |
} |
194 |
|
195 |
/* Basic flow
|
196 |
|
197 |
Server Client
|
198 |
|
199 |
Negotiate
|
200 |
Request
|
201 |
Response
|
202 |
Request
|
203 |
Response
|
204 |
...
|
205 |
...
|
206 |
Request (type == 2)
|
207 |
*/
|
208 |
|
209 |
static int nbd_send_negotiate(int csock, off_t size, uint32_t flags) |
210 |
{ |
211 |
char buf[8 + 8 + 8 + 128]; |
212 |
int rc;
|
213 |
|
214 |
/* Negotiate
|
215 |
[ 0 .. 7] passwd ("NBDMAGIC")
|
216 |
[ 8 .. 15] magic (0x00420281861253)
|
217 |
[16 .. 23] size
|
218 |
[24 .. 27] flags
|
219 |
[28 .. 151] reserved (0)
|
220 |
*/
|
221 |
|
222 |
socket_set_block(csock); |
223 |
rc = -EINVAL; |
224 |
|
225 |
TRACE("Beginning negotiation.");
|
226 |
memcpy(buf, "NBDMAGIC", 8); |
227 |
cpu_to_be64w((uint64_t*)(buf + 8), 0x00420281861253LL); |
228 |
cpu_to_be64w((uint64_t*)(buf + 16), size);
|
229 |
cpu_to_be32w((uint32_t*)(buf + 24),
|
230 |
flags | NBD_FLAG_HAS_FLAGS | NBD_FLAG_SEND_TRIM | |
231 |
NBD_FLAG_SEND_FLUSH | NBD_FLAG_SEND_FUA); |
232 |
memset(buf + 28, 0, 124); |
233 |
|
234 |
if (write_sync(csock, buf, sizeof(buf)) != sizeof(buf)) { |
235 |
LOG("write failed");
|
236 |
goto fail;
|
237 |
} |
238 |
|
239 |
TRACE("Negotiation succeeded.");
|
240 |
rc = 0;
|
241 |
fail:
|
242 |
socket_set_nonblock(csock); |
243 |
return rc;
|
244 |
} |
245 |
|
246 |
int nbd_receive_negotiate(int csock, const char *name, uint32_t *flags, |
247 |
off_t *size, size_t *blocksize) |
248 |
{ |
249 |
char buf[256]; |
250 |
uint64_t magic, s; |
251 |
uint16_t tmp; |
252 |
int rc;
|
253 |
|
254 |
TRACE("Receiving negotiation.");
|
255 |
|
256 |
socket_set_block(csock); |
257 |
rc = -EINVAL; |
258 |
|
259 |
if (read_sync(csock, buf, 8) != 8) { |
260 |
LOG("read failed");
|
261 |
goto fail;
|
262 |
} |
263 |
|
264 |
buf[8] = '\0'; |
265 |
if (strlen(buf) == 0) { |
266 |
LOG("server connection closed");
|
267 |
goto fail;
|
268 |
} |
269 |
|
270 |
TRACE("Magic is %c%c%c%c%c%c%c%c",
|
271 |
qemu_isprint(buf[0]) ? buf[0] : '.', |
272 |
qemu_isprint(buf[1]) ? buf[1] : '.', |
273 |
qemu_isprint(buf[2]) ? buf[2] : '.', |
274 |
qemu_isprint(buf[3]) ? buf[3] : '.', |
275 |
qemu_isprint(buf[4]) ? buf[4] : '.', |
276 |
qemu_isprint(buf[5]) ? buf[5] : '.', |
277 |
qemu_isprint(buf[6]) ? buf[6] : '.', |
278 |
qemu_isprint(buf[7]) ? buf[7] : '.'); |
279 |
|
280 |
if (memcmp(buf, "NBDMAGIC", 8) != 0) { |
281 |
LOG("Invalid magic received");
|
282 |
goto fail;
|
283 |
} |
284 |
|
285 |
if (read_sync(csock, &magic, sizeof(magic)) != sizeof(magic)) { |
286 |
LOG("read failed");
|
287 |
goto fail;
|
288 |
} |
289 |
magic = be64_to_cpu(magic); |
290 |
TRACE("Magic is 0x%" PRIx64, magic);
|
291 |
|
292 |
if (name) {
|
293 |
uint32_t reserved = 0;
|
294 |
uint32_t opt; |
295 |
uint32_t namesize; |
296 |
|
297 |
TRACE("Checking magic (opts_magic)");
|
298 |
if (magic != 0x49484156454F5054LL) { |
299 |
LOG("Bad magic received");
|
300 |
goto fail;
|
301 |
} |
302 |
if (read_sync(csock, &tmp, sizeof(tmp)) != sizeof(tmp)) { |
303 |
LOG("flags read failed");
|
304 |
goto fail;
|
305 |
} |
306 |
*flags = be16_to_cpu(tmp) << 16;
|
307 |
/* reserved for future use */
|
308 |
if (write_sync(csock, &reserved, sizeof(reserved)) != |
309 |
sizeof(reserved)) {
|
310 |
LOG("write failed (reserved)");
|
311 |
goto fail;
|
312 |
} |
313 |
/* write the export name */
|
314 |
magic = cpu_to_be64(magic); |
315 |
if (write_sync(csock, &magic, sizeof(magic)) != sizeof(magic)) { |
316 |
LOG("write failed (magic)");
|
317 |
goto fail;
|
318 |
} |
319 |
opt = cpu_to_be32(NBD_OPT_EXPORT_NAME); |
320 |
if (write_sync(csock, &opt, sizeof(opt)) != sizeof(opt)) { |
321 |
LOG("write failed (opt)");
|
322 |
goto fail;
|
323 |
} |
324 |
namesize = cpu_to_be32(strlen(name)); |
325 |
if (write_sync(csock, &namesize, sizeof(namesize)) != |
326 |
sizeof(namesize)) {
|
327 |
LOG("write failed (namesize)");
|
328 |
goto fail;
|
329 |
} |
330 |
if (write_sync(csock, (char*)name, strlen(name)) != strlen(name)) { |
331 |
LOG("write failed (name)");
|
332 |
goto fail;
|
333 |
} |
334 |
} else {
|
335 |
TRACE("Checking magic (cli_magic)");
|
336 |
|
337 |
if (magic != 0x00420281861253LL) { |
338 |
LOG("Bad magic received");
|
339 |
goto fail;
|
340 |
} |
341 |
} |
342 |
|
343 |
if (read_sync(csock, &s, sizeof(s)) != sizeof(s)) { |
344 |
LOG("read failed");
|
345 |
goto fail;
|
346 |
} |
347 |
*size = be64_to_cpu(s); |
348 |
*blocksize = 1024;
|
349 |
TRACE("Size is %" PRIu64, *size);
|
350 |
|
351 |
if (!name) {
|
352 |
if (read_sync(csock, flags, sizeof(*flags)) != sizeof(*flags)) { |
353 |
LOG("read failed (flags)");
|
354 |
goto fail;
|
355 |
} |
356 |
*flags = be32_to_cpup(flags); |
357 |
} else {
|
358 |
if (read_sync(csock, &tmp, sizeof(tmp)) != sizeof(tmp)) { |
359 |
LOG("read failed (tmp)");
|
360 |
goto fail;
|
361 |
} |
362 |
*flags |= be32_to_cpu(tmp); |
363 |
} |
364 |
if (read_sync(csock, &buf, 124) != 124) { |
365 |
LOG("read failed (buf)");
|
366 |
goto fail;
|
367 |
} |
368 |
rc = 0;
|
369 |
|
370 |
fail:
|
371 |
socket_set_nonblock(csock); |
372 |
return rc;
|
373 |
} |
374 |
|
375 |
#ifdef __linux__
|
376 |
int nbd_init(int fd, int csock, uint32_t flags, off_t size, size_t blocksize) |
377 |
{ |
378 |
TRACE("Setting NBD socket");
|
379 |
|
380 |
if (ioctl(fd, NBD_SET_SOCK, csock) < 0) { |
381 |
int serrno = errno;
|
382 |
LOG("Failed to set NBD socket");
|
383 |
return -serrno;
|
384 |
} |
385 |
|
386 |
TRACE("Setting block size to %lu", (unsigned long)blocksize); |
387 |
|
388 |
if (ioctl(fd, NBD_SET_BLKSIZE, blocksize) < 0) { |
389 |
int serrno = errno;
|
390 |
LOG("Failed setting NBD block size");
|
391 |
return -serrno;
|
392 |
} |
393 |
|
394 |
TRACE("Setting size to %zd block(s)", (size_t)(size / blocksize));
|
395 |
|
396 |
if (ioctl(fd, NBD_SET_SIZE_BLOCKS, size / blocksize) < 0) { |
397 |
int serrno = errno;
|
398 |
LOG("Failed setting size (in blocks)");
|
399 |
return -serrno;
|
400 |
} |
401 |
|
402 |
if (flags & NBD_FLAG_READ_ONLY) {
|
403 |
int read_only = 1; |
404 |
TRACE("Setting readonly attribute");
|
405 |
|
406 |
if (ioctl(fd, BLKROSET, (unsigned long) &read_only) < 0) { |
407 |
int serrno = errno;
|
408 |
LOG("Failed setting read-only attribute");
|
409 |
return -serrno;
|
410 |
} |
411 |
} |
412 |
|
413 |
if (ioctl(fd, NBD_SET_FLAGS, flags) < 0 |
414 |
&& errno != ENOTTY) { |
415 |
int serrno = errno;
|
416 |
LOG("Failed setting flags");
|
417 |
return -serrno;
|
418 |
} |
419 |
|
420 |
TRACE("Negotiation ended");
|
421 |
|
422 |
return 0; |
423 |
} |
424 |
|
425 |
int nbd_disconnect(int fd) |
426 |
{ |
427 |
ioctl(fd, NBD_CLEAR_QUE); |
428 |
ioctl(fd, NBD_DISCONNECT); |
429 |
ioctl(fd, NBD_CLEAR_SOCK); |
430 |
return 0; |
431 |
} |
432 |
|
433 |
int nbd_client(int fd) |
434 |
{ |
435 |
int ret;
|
436 |
int serrno;
|
437 |
|
438 |
TRACE("Doing NBD loop");
|
439 |
|
440 |
ret = ioctl(fd, NBD_DO_IT); |
441 |
if (ret < 0 && errno == EPIPE) { |
442 |
/* NBD_DO_IT normally returns EPIPE when someone has disconnected
|
443 |
* the socket via NBD_DISCONNECT. We do not want to return 1 in
|
444 |
* that case.
|
445 |
*/
|
446 |
ret = 0;
|
447 |
} |
448 |
serrno = errno; |
449 |
|
450 |
TRACE("NBD loop returned %d: %s", ret, strerror(serrno));
|
451 |
|
452 |
TRACE("Clearing NBD queue");
|
453 |
ioctl(fd, NBD_CLEAR_QUE); |
454 |
|
455 |
TRACE("Clearing NBD socket");
|
456 |
ioctl(fd, NBD_CLEAR_SOCK); |
457 |
|
458 |
errno = serrno; |
459 |
return ret;
|
460 |
} |
461 |
#else
|
462 |
int nbd_init(int fd, int csock, uint32_t flags, off_t size, size_t blocksize) |
463 |
{ |
464 |
return -ENOTSUP;
|
465 |
} |
466 |
|
467 |
int nbd_disconnect(int fd) |
468 |
{ |
469 |
return -ENOTSUP;
|
470 |
} |
471 |
|
472 |
int nbd_client(int fd) |
473 |
{ |
474 |
return -ENOTSUP;
|
475 |
} |
476 |
#endif
|
477 |
|
478 |
ssize_t nbd_send_request(int csock, struct nbd_request *request) |
479 |
{ |
480 |
uint8_t buf[4 + 4 + 8 + 8 + 4]; |
481 |
ssize_t ret; |
482 |
|
483 |
cpu_to_be32w((uint32_t*)buf, NBD_REQUEST_MAGIC); |
484 |
cpu_to_be32w((uint32_t*)(buf + 4), request->type);
|
485 |
cpu_to_be64w((uint64_t*)(buf + 8), request->handle);
|
486 |
cpu_to_be64w((uint64_t*)(buf + 16), request->from);
|
487 |
cpu_to_be32w((uint32_t*)(buf + 24), request->len);
|
488 |
|
489 |
TRACE("Sending request to client: "
|
490 |
"{ .from = %" PRIu64", .len = %u, .handle = %" PRIu64", .type=%i}", |
491 |
request->from, request->len, request->handle, request->type); |
492 |
|
493 |
ret = write_sync(csock, buf, sizeof(buf));
|
494 |
if (ret < 0) { |
495 |
return ret;
|
496 |
} |
497 |
|
498 |
if (ret != sizeof(buf)) { |
499 |
LOG("writing to socket failed");
|
500 |
return -EINVAL;
|
501 |
} |
502 |
return 0; |
503 |
} |
504 |
|
505 |
static ssize_t nbd_receive_request(int csock, struct nbd_request *request) |
506 |
{ |
507 |
uint8_t buf[4 + 4 + 8 + 8 + 4]; |
508 |
uint32_t magic; |
509 |
ssize_t ret; |
510 |
|
511 |
ret = read_sync(csock, buf, sizeof(buf));
|
512 |
if (ret < 0) { |
513 |
return ret;
|
514 |
} |
515 |
|
516 |
if (ret != sizeof(buf)) { |
517 |
LOG("read failed");
|
518 |
return -EINVAL;
|
519 |
} |
520 |
|
521 |
/* Request
|
522 |
[ 0 .. 3] magic (NBD_REQUEST_MAGIC)
|
523 |
[ 4 .. 7] type (0 == READ, 1 == WRITE)
|
524 |
[ 8 .. 15] handle
|
525 |
[16 .. 23] from
|
526 |
[24 .. 27] len
|
527 |
*/
|
528 |
|
529 |
magic = be32_to_cpup((uint32_t*)buf); |
530 |
request->type = be32_to_cpup((uint32_t*)(buf + 4));
|
531 |
request->handle = be64_to_cpup((uint64_t*)(buf + 8));
|
532 |
request->from = be64_to_cpup((uint64_t*)(buf + 16));
|
533 |
request->len = be32_to_cpup((uint32_t*)(buf + 24));
|
534 |
|
535 |
TRACE("Got request: "
|
536 |
"{ magic = 0x%x, .type = %d, from = %" PRIu64" , len = %u }", |
537 |
magic, request->type, request->from, request->len); |
538 |
|
539 |
if (magic != NBD_REQUEST_MAGIC) {
|
540 |
LOG("invalid magic (got 0x%x)", magic);
|
541 |
return -EINVAL;
|
542 |
} |
543 |
return 0; |
544 |
} |
545 |
|
546 |
ssize_t nbd_receive_reply(int csock, struct nbd_reply *reply) |
547 |
{ |
548 |
uint8_t buf[NBD_REPLY_SIZE]; |
549 |
uint32_t magic; |
550 |
ssize_t ret; |
551 |
|
552 |
ret = read_sync(csock, buf, sizeof(buf));
|
553 |
if (ret < 0) { |
554 |
return ret;
|
555 |
} |
556 |
|
557 |
if (ret != sizeof(buf)) { |
558 |
LOG("read failed");
|
559 |
return -EINVAL;
|
560 |
} |
561 |
|
562 |
/* Reply
|
563 |
[ 0 .. 3] magic (NBD_REPLY_MAGIC)
|
564 |
[ 4 .. 7] error (0 == no error)
|
565 |
[ 7 .. 15] handle
|
566 |
*/
|
567 |
|
568 |
magic = be32_to_cpup((uint32_t*)buf); |
569 |
reply->error = be32_to_cpup((uint32_t*)(buf + 4));
|
570 |
reply->handle = be64_to_cpup((uint64_t*)(buf + 8));
|
571 |
|
572 |
TRACE("Got reply: "
|
573 |
"{ magic = 0x%x, .error = %d, handle = %" PRIu64" }", |
574 |
magic, reply->error, reply->handle); |
575 |
|
576 |
if (magic != NBD_REPLY_MAGIC) {
|
577 |
LOG("invalid magic (got 0x%x)", magic);
|
578 |
return -EINVAL;
|
579 |
} |
580 |
return 0; |
581 |
} |
582 |
|
583 |
static ssize_t nbd_send_reply(int csock, struct nbd_reply *reply) |
584 |
{ |
585 |
uint8_t buf[4 + 4 + 8]; |
586 |
ssize_t ret; |
587 |
|
588 |
/* Reply
|
589 |
[ 0 .. 3] magic (NBD_REPLY_MAGIC)
|
590 |
[ 4 .. 7] error (0 == no error)
|
591 |
[ 7 .. 15] handle
|
592 |
*/
|
593 |
cpu_to_be32w((uint32_t*)buf, NBD_REPLY_MAGIC); |
594 |
cpu_to_be32w((uint32_t*)(buf + 4), reply->error);
|
595 |
cpu_to_be64w((uint64_t*)(buf + 8), reply->handle);
|
596 |
|
597 |
TRACE("Sending response to client");
|
598 |
|
599 |
ret = write_sync(csock, buf, sizeof(buf));
|
600 |
if (ret < 0) { |
601 |
return ret;
|
602 |
} |
603 |
|
604 |
if (ret != sizeof(buf)) { |
605 |
LOG("writing to socket failed");
|
606 |
return -EINVAL;
|
607 |
} |
608 |
return 0; |
609 |
} |
610 |
|
611 |
#define MAX_NBD_REQUESTS 16 |
612 |
|
613 |
typedef struct NBDRequest NBDRequest; |
614 |
|
615 |
struct NBDRequest {
|
616 |
QSIMPLEQ_ENTRY(NBDRequest) entry; |
617 |
NBDClient *client; |
618 |
uint8_t *data; |
619 |
}; |
620 |
|
621 |
struct NBDExport {
|
622 |
BlockDriverState *bs; |
623 |
off_t dev_offset; |
624 |
off_t size; |
625 |
uint32_t nbdflags; |
626 |
QSIMPLEQ_HEAD(, NBDRequest) requests; |
627 |
}; |
628 |
|
629 |
struct NBDClient {
|
630 |
int refcount;
|
631 |
void (*close)(NBDClient *client);
|
632 |
|
633 |
NBDExport *exp; |
634 |
int sock;
|
635 |
|
636 |
Coroutine *recv_coroutine; |
637 |
|
638 |
CoMutex send_lock; |
639 |
Coroutine *send_coroutine; |
640 |
|
641 |
int nb_requests;
|
642 |
}; |
643 |
|
644 |
static void nbd_client_get(NBDClient *client) |
645 |
{ |
646 |
client->refcount++; |
647 |
} |
648 |
|
649 |
static void nbd_client_put(NBDClient *client) |
650 |
{ |
651 |
if (--client->refcount == 0) { |
652 |
g_free(client); |
653 |
} |
654 |
} |
655 |
|
656 |
static void nbd_client_close(NBDClient *client) |
657 |
{ |
658 |
qemu_set_fd_handler2(client->sock, NULL, NULL, NULL, NULL); |
659 |
close(client->sock); |
660 |
client->sock = -1;
|
661 |
if (client->close) {
|
662 |
client->close(client); |
663 |
} |
664 |
nbd_client_put(client); |
665 |
} |
666 |
|
667 |
static NBDRequest *nbd_request_get(NBDClient *client)
|
668 |
{ |
669 |
NBDRequest *req; |
670 |
NBDExport *exp = client->exp; |
671 |
|
672 |
assert(client->nb_requests <= MAX_NBD_REQUESTS - 1);
|
673 |
client->nb_requests++; |
674 |
|
675 |
if (QSIMPLEQ_EMPTY(&exp->requests)) {
|
676 |
req = g_malloc0(sizeof(NBDRequest));
|
677 |
req->data = qemu_blockalign(exp->bs, NBD_BUFFER_SIZE); |
678 |
} else {
|
679 |
req = QSIMPLEQ_FIRST(&exp->requests); |
680 |
QSIMPLEQ_REMOVE_HEAD(&exp->requests, entry); |
681 |
} |
682 |
nbd_client_get(client); |
683 |
req->client = client; |
684 |
return req;
|
685 |
} |
686 |
|
687 |
static void nbd_request_put(NBDRequest *req) |
688 |
{ |
689 |
NBDClient *client = req->client; |
690 |
QSIMPLEQ_INSERT_HEAD(&client->exp->requests, req, entry); |
691 |
if (client->nb_requests-- == MAX_NBD_REQUESTS) {
|
692 |
qemu_notify_event(); |
693 |
} |
694 |
nbd_client_put(client); |
695 |
} |
696 |
|
697 |
NBDExport *nbd_export_new(BlockDriverState *bs, off_t dev_offset, |
698 |
off_t size, uint32_t nbdflags) |
699 |
{ |
700 |
NBDExport *exp = g_malloc0(sizeof(NBDExport));
|
701 |
QSIMPLEQ_INIT(&exp->requests); |
702 |
exp->bs = bs; |
703 |
exp->dev_offset = dev_offset; |
704 |
exp->nbdflags = nbdflags; |
705 |
exp->size = size == -1 ? bdrv_getlength(bs) : size;
|
706 |
return exp;
|
707 |
} |
708 |
|
709 |
void nbd_export_close(NBDExport *exp)
|
710 |
{ |
711 |
while (!QSIMPLEQ_EMPTY(&exp->requests)) {
|
712 |
NBDRequest *first = QSIMPLEQ_FIRST(&exp->requests); |
713 |
QSIMPLEQ_REMOVE_HEAD(&exp->requests, entry); |
714 |
qemu_vfree(first->data); |
715 |
g_free(first); |
716 |
} |
717 |
|
718 |
bdrv_close(exp->bs); |
719 |
g_free(exp); |
720 |
} |
721 |
|
722 |
static int nbd_can_read(void *opaque); |
723 |
static void nbd_read(void *opaque); |
724 |
static void nbd_restart_write(void *opaque); |
725 |
|
726 |
static ssize_t nbd_co_send_reply(NBDRequest *req, struct nbd_reply *reply, |
727 |
int len)
|
728 |
{ |
729 |
NBDClient *client = req->client; |
730 |
int csock = client->sock;
|
731 |
ssize_t rc, ret; |
732 |
|
733 |
qemu_co_mutex_lock(&client->send_lock); |
734 |
qemu_set_fd_handler2(csock, nbd_can_read, nbd_read, |
735 |
nbd_restart_write, client); |
736 |
client->send_coroutine = qemu_coroutine_self(); |
737 |
|
738 |
if (!len) {
|
739 |
rc = nbd_send_reply(csock, reply); |
740 |
} else {
|
741 |
socket_set_cork(csock, 1);
|
742 |
rc = nbd_send_reply(csock, reply); |
743 |
if (rc >= 0) { |
744 |
ret = qemu_co_send(csock, req->data, len); |
745 |
if (ret != len) {
|
746 |
rc = -EIO; |
747 |
} |
748 |
} |
749 |
socket_set_cork(csock, 0);
|
750 |
} |
751 |
|
752 |
client->send_coroutine = NULL;
|
753 |
qemu_set_fd_handler2(csock, nbd_can_read, nbd_read, NULL, client);
|
754 |
qemu_co_mutex_unlock(&client->send_lock); |
755 |
return rc;
|
756 |
} |
757 |
|
758 |
static ssize_t nbd_co_receive_request(NBDRequest *req, struct nbd_request *request) |
759 |
{ |
760 |
NBDClient *client = req->client; |
761 |
int csock = client->sock;
|
762 |
ssize_t rc; |
763 |
|
764 |
client->recv_coroutine = qemu_coroutine_self(); |
765 |
rc = nbd_receive_request(csock, request); |
766 |
if (rc < 0) { |
767 |
if (rc != -EAGAIN) {
|
768 |
rc = -EIO; |
769 |
} |
770 |
goto out;
|
771 |
} |
772 |
|
773 |
if (request->len > NBD_BUFFER_SIZE) {
|
774 |
LOG("len (%u) is larger than max len (%u)",
|
775 |
request->len, NBD_BUFFER_SIZE); |
776 |
rc = -EINVAL; |
777 |
goto out;
|
778 |
} |
779 |
|
780 |
if ((request->from + request->len) < request->from) {
|
781 |
LOG("integer overflow detected! "
|
782 |
"you're probably being attacked");
|
783 |
rc = -EINVAL; |
784 |
goto out;
|
785 |
} |
786 |
|
787 |
TRACE("Decoding type");
|
788 |
|
789 |
if ((request->type & NBD_CMD_MASK_COMMAND) == NBD_CMD_WRITE) {
|
790 |
TRACE("Reading %u byte(s)", request->len);
|
791 |
|
792 |
if (qemu_co_recv(csock, req->data, request->len) != request->len) {
|
793 |
LOG("reading from socket failed");
|
794 |
rc = -EIO; |
795 |
goto out;
|
796 |
} |
797 |
} |
798 |
rc = 0;
|
799 |
|
800 |
out:
|
801 |
client->recv_coroutine = NULL;
|
802 |
return rc;
|
803 |
} |
804 |
|
805 |
static void nbd_trip(void *opaque) |
806 |
{ |
807 |
NBDClient *client = opaque; |
808 |
NBDRequest *req = nbd_request_get(client); |
809 |
NBDExport *exp = client->exp; |
810 |
struct nbd_request request;
|
811 |
struct nbd_reply reply;
|
812 |
ssize_t ret; |
813 |
|
814 |
TRACE("Reading request.");
|
815 |
|
816 |
ret = nbd_co_receive_request(req, &request); |
817 |
if (ret == -EAGAIN) {
|
818 |
goto done;
|
819 |
} |
820 |
if (ret == -EIO) {
|
821 |
goto out;
|
822 |
} |
823 |
|
824 |
reply.handle = request.handle; |
825 |
reply.error = 0;
|
826 |
|
827 |
if (ret < 0) { |
828 |
reply.error = -ret; |
829 |
goto error_reply;
|
830 |
} |
831 |
|
832 |
if ((request.from + request.len) > exp->size) {
|
833 |
LOG("From: %" PRIu64 ", Len: %u, Size: %" PRIu64 |
834 |
", Offset: %" PRIu64 "\n", |
835 |
request.from, request.len, |
836 |
(uint64_t)exp->size, (uint64_t)exp->dev_offset); |
837 |
LOG("requested operation past EOF--bad client?");
|
838 |
goto invalid_request;
|
839 |
} |
840 |
|
841 |
switch (request.type & NBD_CMD_MASK_COMMAND) {
|
842 |
case NBD_CMD_READ:
|
843 |
TRACE("Request type is READ");
|
844 |
|
845 |
if (request.type & NBD_CMD_FLAG_FUA) {
|
846 |
ret = bdrv_co_flush(exp->bs); |
847 |
if (ret < 0) { |
848 |
LOG("flush failed");
|
849 |
reply.error = -ret; |
850 |
goto error_reply;
|
851 |
} |
852 |
} |
853 |
|
854 |
ret = bdrv_read(exp->bs, (request.from + exp->dev_offset) / 512,
|
855 |
req->data, request.len / 512);
|
856 |
if (ret < 0) { |
857 |
LOG("reading from file failed");
|
858 |
reply.error = -ret; |
859 |
goto error_reply;
|
860 |
} |
861 |
|
862 |
TRACE("Read %u byte(s)", request.len);
|
863 |
if (nbd_co_send_reply(req, &reply, request.len) < 0) |
864 |
goto out;
|
865 |
break;
|
866 |
case NBD_CMD_WRITE:
|
867 |
TRACE("Request type is WRITE");
|
868 |
|
869 |
if (exp->nbdflags & NBD_FLAG_READ_ONLY) {
|
870 |
TRACE("Server is read-only, return error");
|
871 |
reply.error = EROFS; |
872 |
goto error_reply;
|
873 |
} |
874 |
|
875 |
TRACE("Writing to device");
|
876 |
|
877 |
ret = bdrv_write(exp->bs, (request.from + exp->dev_offset) / 512,
|
878 |
req->data, request.len / 512);
|
879 |
if (ret < 0) { |
880 |
LOG("writing to file failed");
|
881 |
reply.error = -ret; |
882 |
goto error_reply;
|
883 |
} |
884 |
|
885 |
if (request.type & NBD_CMD_FLAG_FUA) {
|
886 |
ret = bdrv_co_flush(exp->bs); |
887 |
if (ret < 0) { |
888 |
LOG("flush failed");
|
889 |
reply.error = -ret; |
890 |
goto error_reply;
|
891 |
} |
892 |
} |
893 |
|
894 |
if (nbd_co_send_reply(req, &reply, 0) < 0) { |
895 |
goto out;
|
896 |
} |
897 |
break;
|
898 |
case NBD_CMD_DISC:
|
899 |
TRACE("Request type is DISCONNECT");
|
900 |
errno = 0;
|
901 |
goto out;
|
902 |
case NBD_CMD_FLUSH:
|
903 |
TRACE("Request type is FLUSH");
|
904 |
|
905 |
ret = bdrv_co_flush(exp->bs); |
906 |
if (ret < 0) { |
907 |
LOG("flush failed");
|
908 |
reply.error = -ret; |
909 |
} |
910 |
if (nbd_co_send_reply(req, &reply, 0) < 0) { |
911 |
goto out;
|
912 |
} |
913 |
break;
|
914 |
case NBD_CMD_TRIM:
|
915 |
TRACE("Request type is TRIM");
|
916 |
ret = bdrv_co_discard(exp->bs, (request.from + exp->dev_offset) / 512,
|
917 |
request.len / 512);
|
918 |
if (ret < 0) { |
919 |
LOG("discard failed");
|
920 |
reply.error = -ret; |
921 |
} |
922 |
if (nbd_co_send_reply(req, &reply, 0) < 0) { |
923 |
goto out;
|
924 |
} |
925 |
break;
|
926 |
default:
|
927 |
LOG("invalid request type (%u) received", request.type);
|
928 |
invalid_request:
|
929 |
reply.error = -EINVAL; |
930 |
error_reply:
|
931 |
if (nbd_co_send_reply(req, &reply, 0) < 0) { |
932 |
goto out;
|
933 |
} |
934 |
break;
|
935 |
} |
936 |
|
937 |
TRACE("Request/Reply complete");
|
938 |
|
939 |
done:
|
940 |
nbd_request_put(req); |
941 |
return;
|
942 |
|
943 |
out:
|
944 |
nbd_request_put(req); |
945 |
nbd_client_close(client); |
946 |
} |
947 |
|
948 |
static int nbd_can_read(void *opaque) |
949 |
{ |
950 |
NBDClient *client = opaque; |
951 |
|
952 |
return client->recv_coroutine || client->nb_requests < MAX_NBD_REQUESTS;
|
953 |
} |
954 |
|
955 |
static void nbd_read(void *opaque) |
956 |
{ |
957 |
NBDClient *client = opaque; |
958 |
|
959 |
if (client->recv_coroutine) {
|
960 |
qemu_coroutine_enter(client->recv_coroutine, NULL);
|
961 |
} else {
|
962 |
qemu_coroutine_enter(qemu_coroutine_create(nbd_trip), client); |
963 |
} |
964 |
} |
965 |
|
966 |
static void nbd_restart_write(void *opaque) |
967 |
{ |
968 |
NBDClient *client = opaque; |
969 |
|
970 |
qemu_coroutine_enter(client->send_coroutine, NULL);
|
971 |
} |
972 |
|
973 |
NBDClient *nbd_client_new(NBDExport *exp, int csock,
|
974 |
void (*close)(NBDClient *))
|
975 |
{ |
976 |
NBDClient *client; |
977 |
if (nbd_send_negotiate(csock, exp->size, exp->nbdflags) < 0) { |
978 |
return NULL; |
979 |
} |
980 |
client = g_malloc0(sizeof(NBDClient));
|
981 |
client->refcount = 1;
|
982 |
client->exp = exp; |
983 |
client->sock = csock; |
984 |
client->close = close; |
985 |
qemu_co_mutex_init(&client->send_lock); |
986 |
qemu_set_fd_handler2(csock, nbd_can_read, nbd_read, NULL, client);
|
987 |
return client;
|
988 |
} |