usb: Fix usb-bt-dongle initialization.
[qemu-kvm.git] / nbd.c
blobe7d1ceec436f3f853a36c9610b095c5b1acfdf59
1 /*
2 * Copyright (C) 2005 Anthony Liguori <anthony@codemonkey.ws>
4 * Network Block Device
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.
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.
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/>.
19 #include "block/nbd.h"
20 #include "block/block.h"
22 #include "block/coroutine.h"
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>
35 #ifdef __linux__
36 #include <linux/fs.h>
37 #endif
39 #include "qemu/sockets.h"
40 #include "qemu/queue.h"
41 #include "qemu/main-loop.h"
43 //#define DEBUG_NBD
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
54 #define LOG(msg, ...) do { \
55 fprintf(stderr, "%s:%s():L%d: " msg "\n", \
56 __FILE__, __FUNCTION__, __LINE__, ## __VA_ARGS__); \
57 } while(0)
59 /* This is all part of the "official" NBD API.
61 * The most up-to-date documentation is available at:
62 * https://github.com/yoe/nbd/blob/master/doc/proto.txt
65 #define NBD_REQUEST_SIZE (4 + 4 + 8 + 8 + 4)
66 #define NBD_REPLY_SIZE (4 + 4 + 8)
67 #define NBD_REQUEST_MAGIC 0x25609513
68 #define NBD_REPLY_MAGIC 0x67446698
69 #define NBD_OPTS_MAGIC 0x49484156454F5054LL
70 #define NBD_CLIENT_MAGIC 0x0000420281861253LL
71 #define NBD_REP_MAGIC 0x3e889045565a9LL
73 #define NBD_SET_SOCK _IO(0xab, 0)
74 #define NBD_SET_BLKSIZE _IO(0xab, 1)
75 #define NBD_SET_SIZE _IO(0xab, 2)
76 #define NBD_DO_IT _IO(0xab, 3)
77 #define NBD_CLEAR_SOCK _IO(0xab, 4)
78 #define NBD_CLEAR_QUE _IO(0xab, 5)
79 #define NBD_PRINT_DEBUG _IO(0xab, 6)
80 #define NBD_SET_SIZE_BLOCKS _IO(0xab, 7)
81 #define NBD_DISCONNECT _IO(0xab, 8)
82 #define NBD_SET_TIMEOUT _IO(0xab, 9)
83 #define NBD_SET_FLAGS _IO(0xab, 10)
85 #define NBD_OPT_EXPORT_NAME (1)
86 #define NBD_OPT_ABORT (2)
87 #define NBD_OPT_LIST (3)
89 /* Definitions for opaque data types */
91 typedef struct NBDRequest NBDRequest;
93 struct NBDRequest {
94 QSIMPLEQ_ENTRY(NBDRequest) entry;
95 NBDClient *client;
96 uint8_t *data;
99 struct NBDExport {
100 int refcount;
101 void (*close)(NBDExport *exp);
103 BlockDriverState *bs;
104 char *name;
105 off_t dev_offset;
106 off_t size;
107 uint32_t nbdflags;
108 QTAILQ_HEAD(, NBDClient) clients;
109 QTAILQ_ENTRY(NBDExport) next;
112 static QTAILQ_HEAD(, NBDExport) exports = QTAILQ_HEAD_INITIALIZER(exports);
114 struct NBDClient {
115 int refcount;
116 void (*close)(NBDClient *client);
118 NBDExport *exp;
119 int sock;
121 Coroutine *recv_coroutine;
123 CoMutex send_lock;
124 Coroutine *send_coroutine;
126 QTAILQ_ENTRY(NBDClient) next;
127 int nb_requests;
128 bool closing;
131 /* That's all folks */
133 ssize_t nbd_wr_sync(int fd, void *buffer, size_t size, bool do_read)
135 size_t offset = 0;
136 int err;
138 if (qemu_in_coroutine()) {
139 if (do_read) {
140 return qemu_co_recv(fd, buffer, size);
141 } else {
142 return qemu_co_send(fd, buffer, size);
146 while (offset < size) {
147 ssize_t len;
149 if (do_read) {
150 len = qemu_recv(fd, buffer + offset, size - offset, 0);
151 } else {
152 len = send(fd, buffer + offset, size - offset, 0);
155 if (len < 0) {
156 err = socket_error();
158 /* recoverable error */
159 if (err == EINTR || (offset > 0 && err == EAGAIN)) {
160 continue;
163 /* unrecoverable error */
164 return -err;
167 /* eof */
168 if (len == 0) {
169 break;
172 offset += len;
175 return offset;
178 static ssize_t read_sync(int fd, void *buffer, size_t size)
180 /* Sockets are kept in blocking mode in the negotiation phase. After
181 * that, a non-readable socket simply means that another thread stole
182 * our request/reply. Synchronization is done with recv_coroutine, so
183 * that this is coroutine-safe.
185 return nbd_wr_sync(fd, buffer, size, true);
188 static ssize_t write_sync(int fd, void *buffer, size_t size)
190 int ret;
191 do {
192 /* For writes, we do expect the socket to be writable. */
193 ret = nbd_wr_sync(fd, buffer, size, false);
194 } while (ret == -EAGAIN);
195 return ret;
198 /* Basic flow for negotiation
200 Server Client
201 Negotiate
205 Server Client
206 Negotiate #1
207 Option
208 Negotiate #2
210 ----
212 followed by
214 Server Client
215 Request
216 Response
217 Request
218 Response
221 Request (type == 2)
225 static int nbd_send_rep(int csock, uint32_t type, uint32_t opt)
227 uint64_t magic;
228 uint32_t len;
230 magic = cpu_to_be64(NBD_REP_MAGIC);
231 if (write_sync(csock, &magic, sizeof(magic)) != sizeof(magic)) {
232 LOG("write failed (rep magic)");
233 return -EINVAL;
235 opt = cpu_to_be32(opt);
236 if (write_sync(csock, &opt, sizeof(opt)) != sizeof(opt)) {
237 LOG("write failed (rep opt)");
238 return -EINVAL;
240 type = cpu_to_be32(type);
241 if (write_sync(csock, &type, sizeof(type)) != sizeof(type)) {
242 LOG("write failed (rep type)");
243 return -EINVAL;
245 len = cpu_to_be32(0);
246 if (write_sync(csock, &len, sizeof(len)) != sizeof(len)) {
247 LOG("write failed (rep data length)");
248 return -EINVAL;
250 return 0;
253 static int nbd_send_rep_list(int csock, NBDExport *exp)
255 uint64_t magic, name_len;
256 uint32_t opt, type, len;
258 name_len = strlen(exp->name);
259 magic = cpu_to_be64(NBD_REP_MAGIC);
260 if (write_sync(csock, &magic, sizeof(magic)) != sizeof(magic)) {
261 LOG("write failed (magic)");
262 return -EINVAL;
264 opt = cpu_to_be32(NBD_OPT_LIST);
265 if (write_sync(csock, &opt, sizeof(opt)) != sizeof(opt)) {
266 LOG("write failed (opt)");
267 return -EINVAL;
269 type = cpu_to_be32(NBD_REP_SERVER);
270 if (write_sync(csock, &type, sizeof(type)) != sizeof(type)) {
271 LOG("write failed (reply type)");
272 return -EINVAL;
274 len = cpu_to_be32(name_len + sizeof(len));
275 if (write_sync(csock, &len, sizeof(len)) != sizeof(len)) {
276 LOG("write failed (length)");
277 return -EINVAL;
279 len = cpu_to_be32(name_len);
280 if (write_sync(csock, &len, sizeof(len)) != sizeof(len)) {
281 LOG("write failed (length)");
282 return -EINVAL;
284 if (write_sync(csock, exp->name, name_len) != name_len) {
285 LOG("write failed (buffer)");
286 return -EINVAL;
288 return 0;
291 static int nbd_handle_list(NBDClient *client, uint32_t length)
293 int csock;
294 NBDExport *exp;
296 csock = client->sock;
297 if (length) {
298 return nbd_send_rep(csock, NBD_REP_ERR_INVALID, NBD_OPT_LIST);
301 /* For each export, send a NBD_REP_SERVER reply. */
302 QTAILQ_FOREACH(exp, &exports, next) {
303 if (nbd_send_rep_list(csock, exp)) {
304 return -EINVAL;
307 /* Finish with a NBD_REP_ACK. */
308 return nbd_send_rep(csock, NBD_REP_ACK, NBD_OPT_LIST);
311 static int nbd_handle_export_name(NBDClient *client, uint32_t length)
313 int rc = -EINVAL, csock = client->sock;
314 char name[256];
316 /* Client sends:
317 [20 .. xx] export name (length bytes)
319 TRACE("Checking length");
320 if (length > 255) {
321 LOG("Bad length received");
322 goto fail;
324 if (read_sync(csock, name, length) != length) {
325 LOG("read failed");
326 goto fail;
328 name[length] = '\0';
330 client->exp = nbd_export_find(name);
331 if (!client->exp) {
332 LOG("export not found");
333 goto fail;
336 QTAILQ_INSERT_TAIL(&client->exp->clients, client, next);
337 nbd_export_get(client->exp);
338 rc = 0;
339 fail:
340 return rc;
343 static int nbd_receive_options(NBDClient *client)
345 while (1) {
346 int csock = client->sock;
347 uint32_t tmp, length;
348 uint64_t magic;
350 /* Client sends:
351 [ 0 .. 3] client flags
352 [ 4 .. 11] NBD_OPTS_MAGIC
353 [12 .. 15] NBD option
354 [16 .. 19] length
355 ... Rest of request
358 if (read_sync(csock, &tmp, sizeof(tmp)) != sizeof(tmp)) {
359 LOG("read failed");
360 return -EINVAL;
362 TRACE("Checking client flags");
363 tmp = be32_to_cpu(tmp);
364 if (tmp != 0 && tmp != NBD_FLAG_C_FIXED_NEWSTYLE) {
365 LOG("Bad client flags received");
366 return -EINVAL;
369 if (read_sync(csock, &magic, sizeof(magic)) != sizeof(magic)) {
370 LOG("read failed");
371 return -EINVAL;
373 TRACE("Checking opts magic");
374 if (magic != be64_to_cpu(NBD_OPTS_MAGIC)) {
375 LOG("Bad magic received");
376 return -EINVAL;
379 if (read_sync(csock, &tmp, sizeof(tmp)) != sizeof(tmp)) {
380 LOG("read failed");
381 return -EINVAL;
384 if (read_sync(csock, &length, sizeof(length)) != sizeof(length)) {
385 LOG("read failed");
386 return -EINVAL;
388 length = be32_to_cpu(length);
390 TRACE("Checking option");
391 switch (be32_to_cpu(tmp)) {
392 case NBD_OPT_LIST:
393 if (nbd_handle_list(client, length) < 0) {
394 return 1;
396 break;
398 case NBD_OPT_ABORT:
399 return -EINVAL;
401 case NBD_OPT_EXPORT_NAME:
402 return nbd_handle_export_name(client, length);
404 default:
405 tmp = be32_to_cpu(tmp);
406 LOG("Unsupported option 0x%x", tmp);
407 nbd_send_rep(client->sock, NBD_REP_ERR_UNSUP, tmp);
408 return -EINVAL;
413 static int nbd_send_negotiate(NBDClient *client)
415 int csock = client->sock;
416 char buf[8 + 8 + 8 + 128];
417 int rc;
418 const int myflags = (NBD_FLAG_HAS_FLAGS | NBD_FLAG_SEND_TRIM |
419 NBD_FLAG_SEND_FLUSH | NBD_FLAG_SEND_FUA);
421 /* Negotiation header without options:
422 [ 0 .. 7] passwd ("NBDMAGIC")
423 [ 8 .. 15] magic (NBD_CLIENT_MAGIC)
424 [16 .. 23] size
425 [24 .. 25] server flags (0)
426 [26 .. 27] export flags
427 [28 .. 151] reserved (0)
429 Negotiation header with options, part 1:
430 [ 0 .. 7] passwd ("NBDMAGIC")
431 [ 8 .. 15] magic (NBD_OPTS_MAGIC)
432 [16 .. 17] server flags (0)
434 part 2 (after options are sent):
435 [18 .. 25] size
436 [26 .. 27] export flags
437 [28 .. 151] reserved (0)
440 qemu_set_block(csock);
441 rc = -EINVAL;
443 TRACE("Beginning negotiation.");
444 memset(buf, 0, sizeof(buf));
445 memcpy(buf, "NBDMAGIC", 8);
446 if (client->exp) {
447 assert ((client->exp->nbdflags & ~65535) == 0);
448 cpu_to_be64w((uint64_t*)(buf + 8), NBD_CLIENT_MAGIC);
449 cpu_to_be64w((uint64_t*)(buf + 16), client->exp->size);
450 cpu_to_be16w((uint16_t*)(buf + 26), client->exp->nbdflags | myflags);
451 } else {
452 cpu_to_be64w((uint64_t*)(buf + 8), NBD_OPTS_MAGIC);
453 cpu_to_be16w((uint16_t *)(buf + 16), NBD_FLAG_FIXED_NEWSTYLE);
456 if (client->exp) {
457 if (write_sync(csock, buf, sizeof(buf)) != sizeof(buf)) {
458 LOG("write failed");
459 goto fail;
461 } else {
462 if (write_sync(csock, buf, 18) != 18) {
463 LOG("write failed");
464 goto fail;
466 rc = nbd_receive_options(client);
467 if (rc != 0) {
468 LOG("option negotiation failed");
469 goto fail;
472 assert ((client->exp->nbdflags & ~65535) == 0);
473 cpu_to_be64w((uint64_t*)(buf + 18), client->exp->size);
474 cpu_to_be16w((uint16_t*)(buf + 26), client->exp->nbdflags | myflags);
475 if (write_sync(csock, buf + 18, sizeof(buf) - 18) != sizeof(buf) - 18) {
476 LOG("write failed");
477 goto fail;
481 TRACE("Negotiation succeeded.");
482 rc = 0;
483 fail:
484 qemu_set_nonblock(csock);
485 return rc;
488 int nbd_receive_negotiate(int csock, const char *name, uint32_t *flags,
489 off_t *size, size_t *blocksize)
491 char buf[256];
492 uint64_t magic, s;
493 uint16_t tmp;
494 int rc;
496 TRACE("Receiving negotiation.");
498 rc = -EINVAL;
500 if (read_sync(csock, buf, 8) != 8) {
501 LOG("read failed");
502 goto fail;
505 buf[8] = '\0';
506 if (strlen(buf) == 0) {
507 LOG("server connection closed");
508 goto fail;
511 TRACE("Magic is %c%c%c%c%c%c%c%c",
512 qemu_isprint(buf[0]) ? buf[0] : '.',
513 qemu_isprint(buf[1]) ? buf[1] : '.',
514 qemu_isprint(buf[2]) ? buf[2] : '.',
515 qemu_isprint(buf[3]) ? buf[3] : '.',
516 qemu_isprint(buf[4]) ? buf[4] : '.',
517 qemu_isprint(buf[5]) ? buf[5] : '.',
518 qemu_isprint(buf[6]) ? buf[6] : '.',
519 qemu_isprint(buf[7]) ? buf[7] : '.');
521 if (memcmp(buf, "NBDMAGIC", 8) != 0) {
522 LOG("Invalid magic received");
523 goto fail;
526 if (read_sync(csock, &magic, sizeof(magic)) != sizeof(magic)) {
527 LOG("read failed");
528 goto fail;
530 magic = be64_to_cpu(magic);
531 TRACE("Magic is 0x%" PRIx64, magic);
533 if (name) {
534 uint32_t reserved = 0;
535 uint32_t opt;
536 uint32_t namesize;
538 TRACE("Checking magic (opts_magic)");
539 if (magic != NBD_OPTS_MAGIC) {
540 LOG("Bad magic received");
541 goto fail;
543 if (read_sync(csock, &tmp, sizeof(tmp)) != sizeof(tmp)) {
544 LOG("flags read failed");
545 goto fail;
547 *flags = be16_to_cpu(tmp) << 16;
548 /* reserved for future use */
549 if (write_sync(csock, &reserved, sizeof(reserved)) !=
550 sizeof(reserved)) {
551 LOG("write failed (reserved)");
552 goto fail;
554 /* write the export name */
555 magic = cpu_to_be64(magic);
556 if (write_sync(csock, &magic, sizeof(magic)) != sizeof(magic)) {
557 LOG("write failed (magic)");
558 goto fail;
560 opt = cpu_to_be32(NBD_OPT_EXPORT_NAME);
561 if (write_sync(csock, &opt, sizeof(opt)) != sizeof(opt)) {
562 LOG("write failed (opt)");
563 goto fail;
565 namesize = cpu_to_be32(strlen(name));
566 if (write_sync(csock, &namesize, sizeof(namesize)) !=
567 sizeof(namesize)) {
568 LOG("write failed (namesize)");
569 goto fail;
571 if (write_sync(csock, (char*)name, strlen(name)) != strlen(name)) {
572 LOG("write failed (name)");
573 goto fail;
575 } else {
576 TRACE("Checking magic (cli_magic)");
578 if (magic != NBD_CLIENT_MAGIC) {
579 LOG("Bad magic received");
580 goto fail;
584 if (read_sync(csock, &s, sizeof(s)) != sizeof(s)) {
585 LOG("read failed");
586 goto fail;
588 *size = be64_to_cpu(s);
589 *blocksize = 1024;
590 TRACE("Size is %" PRIu64, *size);
592 if (!name) {
593 if (read_sync(csock, flags, sizeof(*flags)) != sizeof(*flags)) {
594 LOG("read failed (flags)");
595 goto fail;
597 *flags = be32_to_cpup(flags);
598 } else {
599 if (read_sync(csock, &tmp, sizeof(tmp)) != sizeof(tmp)) {
600 LOG("read failed (tmp)");
601 goto fail;
603 *flags |= be32_to_cpu(tmp);
605 if (read_sync(csock, &buf, 124) != 124) {
606 LOG("read failed (buf)");
607 goto fail;
609 rc = 0;
611 fail:
612 return rc;
615 #ifdef __linux__
616 int nbd_init(int fd, int csock, uint32_t flags, off_t size, size_t blocksize)
618 TRACE("Setting NBD socket");
620 if (ioctl(fd, NBD_SET_SOCK, csock) < 0) {
621 int serrno = errno;
622 LOG("Failed to set NBD socket");
623 return -serrno;
626 TRACE("Setting block size to %lu", (unsigned long)blocksize);
628 if (ioctl(fd, NBD_SET_BLKSIZE, blocksize) < 0) {
629 int serrno = errno;
630 LOG("Failed setting NBD block size");
631 return -serrno;
634 TRACE("Setting size to %zd block(s)", (size_t)(size / blocksize));
636 if (ioctl(fd, NBD_SET_SIZE_BLOCKS, size / blocksize) < 0) {
637 int serrno = errno;
638 LOG("Failed setting size (in blocks)");
639 return -serrno;
642 if (ioctl(fd, NBD_SET_FLAGS, flags) < 0) {
643 if (errno == ENOTTY) {
644 int read_only = (flags & NBD_FLAG_READ_ONLY) != 0;
645 TRACE("Setting readonly attribute");
647 if (ioctl(fd, BLKROSET, (unsigned long) &read_only) < 0) {
648 int serrno = errno;
649 LOG("Failed setting read-only attribute");
650 return -serrno;
652 } else {
653 int serrno = errno;
654 LOG("Failed setting flags");
655 return -serrno;
659 TRACE("Negotiation ended");
661 return 0;
664 int nbd_disconnect(int fd)
666 ioctl(fd, NBD_CLEAR_QUE);
667 ioctl(fd, NBD_DISCONNECT);
668 ioctl(fd, NBD_CLEAR_SOCK);
669 return 0;
672 int nbd_client(int fd)
674 int ret;
675 int serrno;
677 TRACE("Doing NBD loop");
679 ret = ioctl(fd, NBD_DO_IT);
680 if (ret < 0 && errno == EPIPE) {
681 /* NBD_DO_IT normally returns EPIPE when someone has disconnected
682 * the socket via NBD_DISCONNECT. We do not want to return 1 in
683 * that case.
685 ret = 0;
687 serrno = errno;
689 TRACE("NBD loop returned %d: %s", ret, strerror(serrno));
691 TRACE("Clearing NBD queue");
692 ioctl(fd, NBD_CLEAR_QUE);
694 TRACE("Clearing NBD socket");
695 ioctl(fd, NBD_CLEAR_SOCK);
697 errno = serrno;
698 return ret;
700 #else
701 int nbd_init(int fd, int csock, uint32_t flags, off_t size, size_t blocksize)
703 return -ENOTSUP;
706 int nbd_disconnect(int fd)
708 return -ENOTSUP;
711 int nbd_client(int fd)
713 return -ENOTSUP;
715 #endif
717 ssize_t nbd_send_request(int csock, struct nbd_request *request)
719 uint8_t buf[NBD_REQUEST_SIZE];
720 ssize_t ret;
722 cpu_to_be32w((uint32_t*)buf, NBD_REQUEST_MAGIC);
723 cpu_to_be32w((uint32_t*)(buf + 4), request->type);
724 cpu_to_be64w((uint64_t*)(buf + 8), request->handle);
725 cpu_to_be64w((uint64_t*)(buf + 16), request->from);
726 cpu_to_be32w((uint32_t*)(buf + 24), request->len);
728 TRACE("Sending request to client: "
729 "{ .from = %" PRIu64", .len = %u, .handle = %" PRIu64", .type=%i}",
730 request->from, request->len, request->handle, request->type);
732 ret = write_sync(csock, buf, sizeof(buf));
733 if (ret < 0) {
734 return ret;
737 if (ret != sizeof(buf)) {
738 LOG("writing to socket failed");
739 return -EINVAL;
741 return 0;
744 static ssize_t nbd_receive_request(int csock, struct nbd_request *request)
746 uint8_t buf[NBD_REQUEST_SIZE];
747 uint32_t magic;
748 ssize_t ret;
750 ret = read_sync(csock, buf, sizeof(buf));
751 if (ret < 0) {
752 return ret;
755 if (ret != sizeof(buf)) {
756 LOG("read failed");
757 return -EINVAL;
760 /* Request
761 [ 0 .. 3] magic (NBD_REQUEST_MAGIC)
762 [ 4 .. 7] type (0 == READ, 1 == WRITE)
763 [ 8 .. 15] handle
764 [16 .. 23] from
765 [24 .. 27] len
768 magic = be32_to_cpup((uint32_t*)buf);
769 request->type = be32_to_cpup((uint32_t*)(buf + 4));
770 request->handle = be64_to_cpup((uint64_t*)(buf + 8));
771 request->from = be64_to_cpup((uint64_t*)(buf + 16));
772 request->len = be32_to_cpup((uint32_t*)(buf + 24));
774 TRACE("Got request: "
775 "{ magic = 0x%x, .type = %d, from = %" PRIu64" , len = %u }",
776 magic, request->type, request->from, request->len);
778 if (magic != NBD_REQUEST_MAGIC) {
779 LOG("invalid magic (got 0x%x)", magic);
780 return -EINVAL;
782 return 0;
785 ssize_t nbd_receive_reply(int csock, struct nbd_reply *reply)
787 uint8_t buf[NBD_REPLY_SIZE];
788 uint32_t magic;
789 ssize_t ret;
791 ret = read_sync(csock, buf, sizeof(buf));
792 if (ret < 0) {
793 return ret;
796 if (ret != sizeof(buf)) {
797 LOG("read failed");
798 return -EINVAL;
801 /* Reply
802 [ 0 .. 3] magic (NBD_REPLY_MAGIC)
803 [ 4 .. 7] error (0 == no error)
804 [ 7 .. 15] handle
807 magic = be32_to_cpup((uint32_t*)buf);
808 reply->error = be32_to_cpup((uint32_t*)(buf + 4));
809 reply->handle = be64_to_cpup((uint64_t*)(buf + 8));
811 TRACE("Got reply: "
812 "{ magic = 0x%x, .error = %d, handle = %" PRIu64" }",
813 magic, reply->error, reply->handle);
815 if (magic != NBD_REPLY_MAGIC) {
816 LOG("invalid magic (got 0x%x)", magic);
817 return -EINVAL;
819 return 0;
822 static ssize_t nbd_send_reply(int csock, struct nbd_reply *reply)
824 uint8_t buf[NBD_REPLY_SIZE];
825 ssize_t ret;
827 /* Reply
828 [ 0 .. 3] magic (NBD_REPLY_MAGIC)
829 [ 4 .. 7] error (0 == no error)
830 [ 7 .. 15] handle
832 cpu_to_be32w((uint32_t*)buf, NBD_REPLY_MAGIC);
833 cpu_to_be32w((uint32_t*)(buf + 4), reply->error);
834 cpu_to_be64w((uint64_t*)(buf + 8), reply->handle);
836 TRACE("Sending response to client");
838 ret = write_sync(csock, buf, sizeof(buf));
839 if (ret < 0) {
840 return ret;
843 if (ret != sizeof(buf)) {
844 LOG("writing to socket failed");
845 return -EINVAL;
847 return 0;
850 #define MAX_NBD_REQUESTS 16
852 void nbd_client_get(NBDClient *client)
854 client->refcount++;
857 void nbd_client_put(NBDClient *client)
859 if (--client->refcount == 0) {
860 /* The last reference should be dropped by client->close,
861 * which is called by nbd_client_close.
863 assert(client->closing);
865 qemu_set_fd_handler2(client->sock, NULL, NULL, NULL, NULL);
866 close(client->sock);
867 client->sock = -1;
868 if (client->exp) {
869 QTAILQ_REMOVE(&client->exp->clients, client, next);
870 nbd_export_put(client->exp);
872 g_free(client);
876 void nbd_client_close(NBDClient *client)
878 if (client->closing) {
879 return;
882 client->closing = true;
884 /* Force requests to finish. They will drop their own references,
885 * then we'll close the socket and free the NBDClient.
887 shutdown(client->sock, 2);
889 /* Also tell the client, so that they release their reference. */
890 if (client->close) {
891 client->close(client);
895 static NBDRequest *nbd_request_get(NBDClient *client)
897 NBDRequest *req;
899 assert(client->nb_requests <= MAX_NBD_REQUESTS - 1);
900 client->nb_requests++;
902 req = g_slice_new0(NBDRequest);
903 nbd_client_get(client);
904 req->client = client;
905 return req;
908 static void nbd_request_put(NBDRequest *req)
910 NBDClient *client = req->client;
912 if (req->data) {
913 qemu_vfree(req->data);
915 g_slice_free(NBDRequest, req);
917 if (client->nb_requests-- == MAX_NBD_REQUESTS) {
918 qemu_notify_event();
920 nbd_client_put(client);
923 NBDExport *nbd_export_new(BlockDriverState *bs, off_t dev_offset,
924 off_t size, uint32_t nbdflags,
925 void (*close)(NBDExport *))
927 NBDExport *exp = g_malloc0(sizeof(NBDExport));
928 exp->refcount = 1;
929 QTAILQ_INIT(&exp->clients);
930 exp->bs = bs;
931 exp->dev_offset = dev_offset;
932 exp->nbdflags = nbdflags;
933 exp->size = size == -1 ? bdrv_getlength(bs) : size;
934 exp->close = close;
935 bdrv_ref(bs);
936 return exp;
939 NBDExport *nbd_export_find(const char *name)
941 NBDExport *exp;
942 QTAILQ_FOREACH(exp, &exports, next) {
943 if (strcmp(name, exp->name) == 0) {
944 return exp;
948 return NULL;
951 void nbd_export_set_name(NBDExport *exp, const char *name)
953 if (exp->name == name) {
954 return;
957 nbd_export_get(exp);
958 if (exp->name != NULL) {
959 g_free(exp->name);
960 exp->name = NULL;
961 QTAILQ_REMOVE(&exports, exp, next);
962 nbd_export_put(exp);
964 if (name != NULL) {
965 nbd_export_get(exp);
966 exp->name = g_strdup(name);
967 QTAILQ_INSERT_TAIL(&exports, exp, next);
969 nbd_export_put(exp);
972 void nbd_export_close(NBDExport *exp)
974 NBDClient *client, *next;
976 nbd_export_get(exp);
977 QTAILQ_FOREACH_SAFE(client, &exp->clients, next, next) {
978 nbd_client_close(client);
980 nbd_export_set_name(exp, NULL);
981 nbd_export_put(exp);
982 if (exp->bs) {
983 bdrv_unref(exp->bs);
984 exp->bs = NULL;
988 void nbd_export_get(NBDExport *exp)
990 assert(exp->refcount > 0);
991 exp->refcount++;
994 void nbd_export_put(NBDExport *exp)
996 assert(exp->refcount > 0);
997 if (exp->refcount == 1) {
998 nbd_export_close(exp);
1001 if (--exp->refcount == 0) {
1002 assert(exp->name == NULL);
1004 if (exp->close) {
1005 exp->close(exp);
1008 g_free(exp);
1012 BlockDriverState *nbd_export_get_blockdev(NBDExport *exp)
1014 return exp->bs;
1017 void nbd_export_close_all(void)
1019 NBDExport *exp, *next;
1021 QTAILQ_FOREACH_SAFE(exp, &exports, next, next) {
1022 nbd_export_close(exp);
1026 static int nbd_can_read(void *opaque);
1027 static void nbd_read(void *opaque);
1028 static void nbd_restart_write(void *opaque);
1030 static ssize_t nbd_co_send_reply(NBDRequest *req, struct nbd_reply *reply,
1031 int len)
1033 NBDClient *client = req->client;
1034 int csock = client->sock;
1035 ssize_t rc, ret;
1037 qemu_co_mutex_lock(&client->send_lock);
1038 qemu_set_fd_handler2(csock, nbd_can_read, nbd_read,
1039 nbd_restart_write, client);
1040 client->send_coroutine = qemu_coroutine_self();
1042 if (!len) {
1043 rc = nbd_send_reply(csock, reply);
1044 } else {
1045 socket_set_cork(csock, 1);
1046 rc = nbd_send_reply(csock, reply);
1047 if (rc >= 0) {
1048 ret = qemu_co_send(csock, req->data, len);
1049 if (ret != len) {
1050 rc = -EIO;
1053 socket_set_cork(csock, 0);
1056 client->send_coroutine = NULL;
1057 qemu_set_fd_handler2(csock, nbd_can_read, nbd_read, NULL, client);
1058 qemu_co_mutex_unlock(&client->send_lock);
1059 return rc;
1062 static ssize_t nbd_co_receive_request(NBDRequest *req, struct nbd_request *request)
1064 NBDClient *client = req->client;
1065 int csock = client->sock;
1066 uint32_t command;
1067 ssize_t rc;
1069 client->recv_coroutine = qemu_coroutine_self();
1070 rc = nbd_receive_request(csock, request);
1071 if (rc < 0) {
1072 if (rc != -EAGAIN) {
1073 rc = -EIO;
1075 goto out;
1078 if (request->len > NBD_MAX_BUFFER_SIZE) {
1079 LOG("len (%u) is larger than max len (%u)",
1080 request->len, NBD_MAX_BUFFER_SIZE);
1081 rc = -EINVAL;
1082 goto out;
1085 if ((request->from + request->len) < request->from) {
1086 LOG("integer overflow detected! "
1087 "you're probably being attacked");
1088 rc = -EINVAL;
1089 goto out;
1092 TRACE("Decoding type");
1094 command = request->type & NBD_CMD_MASK_COMMAND;
1095 if (command == NBD_CMD_READ || command == NBD_CMD_WRITE) {
1096 req->data = qemu_blockalign(client->exp->bs, request->len);
1098 if (command == NBD_CMD_WRITE) {
1099 TRACE("Reading %u byte(s)", request->len);
1101 if (qemu_co_recv(csock, req->data, request->len) != request->len) {
1102 LOG("reading from socket failed");
1103 rc = -EIO;
1104 goto out;
1107 rc = 0;
1109 out:
1110 client->recv_coroutine = NULL;
1111 return rc;
1114 static void nbd_trip(void *opaque)
1116 NBDClient *client = opaque;
1117 NBDExport *exp = client->exp;
1118 NBDRequest *req;
1119 struct nbd_request request;
1120 struct nbd_reply reply;
1121 ssize_t ret;
1122 uint32_t command;
1124 TRACE("Reading request.");
1125 if (client->closing) {
1126 return;
1129 req = nbd_request_get(client);
1130 ret = nbd_co_receive_request(req, &request);
1131 if (ret == -EAGAIN) {
1132 goto done;
1134 if (ret == -EIO) {
1135 goto out;
1138 reply.handle = request.handle;
1139 reply.error = 0;
1141 if (ret < 0) {
1142 reply.error = -ret;
1143 goto error_reply;
1145 command = request.type & NBD_CMD_MASK_COMMAND;
1146 if (command != NBD_CMD_DISC && (request.from + request.len) > exp->size) {
1147 LOG("From: %" PRIu64 ", Len: %u, Size: %" PRIu64
1148 ", Offset: %" PRIu64 "\n",
1149 request.from, request.len,
1150 (uint64_t)exp->size, (uint64_t)exp->dev_offset);
1151 LOG("requested operation past EOF--bad client?");
1152 goto invalid_request;
1155 switch (command) {
1156 case NBD_CMD_READ:
1157 TRACE("Request type is READ");
1159 if (request.type & NBD_CMD_FLAG_FUA) {
1160 ret = bdrv_co_flush(exp->bs);
1161 if (ret < 0) {
1162 LOG("flush failed");
1163 reply.error = -ret;
1164 goto error_reply;
1168 ret = bdrv_read(exp->bs, (request.from + exp->dev_offset) / 512,
1169 req->data, request.len / 512);
1170 if (ret < 0) {
1171 LOG("reading from file failed");
1172 reply.error = -ret;
1173 goto error_reply;
1176 TRACE("Read %u byte(s)", request.len);
1177 if (nbd_co_send_reply(req, &reply, request.len) < 0)
1178 goto out;
1179 break;
1180 case NBD_CMD_WRITE:
1181 TRACE("Request type is WRITE");
1183 if (exp->nbdflags & NBD_FLAG_READ_ONLY) {
1184 TRACE("Server is read-only, return error");
1185 reply.error = EROFS;
1186 goto error_reply;
1189 TRACE("Writing to device");
1191 ret = bdrv_write(exp->bs, (request.from + exp->dev_offset) / 512,
1192 req->data, request.len / 512);
1193 if (ret < 0) {
1194 LOG("writing to file failed");
1195 reply.error = -ret;
1196 goto error_reply;
1199 if (request.type & NBD_CMD_FLAG_FUA) {
1200 ret = bdrv_co_flush(exp->bs);
1201 if (ret < 0) {
1202 LOG("flush failed");
1203 reply.error = -ret;
1204 goto error_reply;
1208 if (nbd_co_send_reply(req, &reply, 0) < 0) {
1209 goto out;
1211 break;
1212 case NBD_CMD_DISC:
1213 TRACE("Request type is DISCONNECT");
1214 errno = 0;
1215 goto out;
1216 case NBD_CMD_FLUSH:
1217 TRACE("Request type is FLUSH");
1219 ret = bdrv_co_flush(exp->bs);
1220 if (ret < 0) {
1221 LOG("flush failed");
1222 reply.error = -ret;
1224 if (nbd_co_send_reply(req, &reply, 0) < 0) {
1225 goto out;
1227 break;
1228 case NBD_CMD_TRIM:
1229 TRACE("Request type is TRIM");
1230 ret = bdrv_co_discard(exp->bs, (request.from + exp->dev_offset) / 512,
1231 request.len / 512);
1232 if (ret < 0) {
1233 LOG("discard failed");
1234 reply.error = -ret;
1236 if (nbd_co_send_reply(req, &reply, 0) < 0) {
1237 goto out;
1239 break;
1240 default:
1241 LOG("invalid request type (%u) received", request.type);
1242 invalid_request:
1243 reply.error = -EINVAL;
1244 error_reply:
1245 if (nbd_co_send_reply(req, &reply, 0) < 0) {
1246 goto out;
1248 break;
1251 TRACE("Request/Reply complete");
1253 done:
1254 nbd_request_put(req);
1255 return;
1257 out:
1258 nbd_request_put(req);
1259 nbd_client_close(client);
1262 static int nbd_can_read(void *opaque)
1264 NBDClient *client = opaque;
1266 return client->recv_coroutine || client->nb_requests < MAX_NBD_REQUESTS;
1269 static void nbd_read(void *opaque)
1271 NBDClient *client = opaque;
1273 if (client->recv_coroutine) {
1274 qemu_coroutine_enter(client->recv_coroutine, NULL);
1275 } else {
1276 qemu_coroutine_enter(qemu_coroutine_create(nbd_trip), client);
1280 static void nbd_restart_write(void *opaque)
1282 NBDClient *client = opaque;
1284 qemu_coroutine_enter(client->send_coroutine, NULL);
1287 NBDClient *nbd_client_new(NBDExport *exp, int csock,
1288 void (*close)(NBDClient *))
1290 NBDClient *client;
1291 client = g_malloc0(sizeof(NBDClient));
1292 client->refcount = 1;
1293 client->exp = exp;
1294 client->sock = csock;
1295 if (nbd_send_negotiate(client)) {
1296 g_free(client);
1297 return NULL;
1299 client->close = close;
1300 qemu_co_mutex_init(&client->send_lock);
1301 qemu_set_fd_handler2(csock, nbd_can_read, nbd_read, NULL, client);
1303 if (exp) {
1304 QTAILQ_INSERT_TAIL(&exp->clients, client, next);
1305 nbd_export_get(exp);
1307 return client;