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