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