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| 1 |
/*
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|---|---|
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* Copyright (C) 2005 Anthony Liguori <anthony@codemonkey.ws>
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*
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* Network Block Device
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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| 8 |
* the Free Software Foundation; under version 2 of the License.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, see <http://www.gnu.org/licenses/>.
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*/
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#include "block/nbd.h" |
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#include "block/block.h" |
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|
| 22 |
#include "block/coroutine.h" |
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|
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#include <errno.h> |
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#include <string.h> |
| 26 |
#ifndef _WIN32
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#include <sys/ioctl.h> |
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#endif
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#if defined(__sun__) || defined(__HAIKU__)
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#include <sys/ioccom.h> |
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#endif
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#include <ctype.h> |
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#include <inttypes.h> |
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|
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#ifdef __linux__
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#include <linux/fs.h> |
| 37 |
#endif
|
| 38 |
|
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#include "qemu/sockets.h" |
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#include "qemu/queue.h" |
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#include "qemu/main-loop.h" |
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|
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//#define DEBUG_NBD
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|
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#ifdef DEBUG_NBD
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#define TRACE(msg, ...) do { \ |
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LOG(msg, ## __VA_ARGS__); \ |
| 48 |
} while(0) |
| 49 |
#else
|
| 50 |
#define TRACE(msg, ...) \
|
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do { } while (0) |
| 52 |
#endif
|
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|
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#define LOG(msg, ...) do { \ |
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fprintf(stderr, "%s:%s():L%d: " msg "\n", \ |
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__FILE__, __FUNCTION__, __LINE__, ## __VA_ARGS__); \ |
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} while(0) |
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|
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/* This is all part of the "official" NBD API */
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|
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#define NBD_REQUEST_SIZE (4 + 4 + 8 + 8 + 4) |
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#define NBD_REPLY_SIZE (4 + 4 + 8) |
| 63 |
#define NBD_REQUEST_MAGIC 0x25609513 |
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#define NBD_REPLY_MAGIC 0x67446698 |
| 65 |
#define NBD_OPTS_MAGIC 0x49484156454F5054LL |
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#define NBD_CLIENT_MAGIC 0x0000420281861253LL |
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|
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#define NBD_SET_SOCK _IO(0xab, 0) |
| 69 |
#define NBD_SET_BLKSIZE _IO(0xab, 1) |
| 70 |
#define NBD_SET_SIZE _IO(0xab, 2) |
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#define NBD_DO_IT _IO(0xab, 3) |
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#define NBD_CLEAR_SOCK _IO(0xab, 4) |
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#define NBD_CLEAR_QUE _IO(0xab, 5) |
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#define NBD_PRINT_DEBUG _IO(0xab, 6) |
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#define NBD_SET_SIZE_BLOCKS _IO(0xab, 7) |
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#define NBD_DISCONNECT _IO(0xab, 8) |
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#define NBD_SET_TIMEOUT _IO(0xab, 9) |
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#define NBD_SET_FLAGS _IO(0xab, 10) |
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|
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#define NBD_OPT_EXPORT_NAME (1 << 0) |
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|
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/* Definitions for opaque data types */
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|
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typedef struct NBDRequest NBDRequest; |
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|
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struct NBDRequest {
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QSIMPLEQ_ENTRY(NBDRequest) entry; |
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NBDClient *client; |
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uint8_t *data; |
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}; |
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|
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struct NBDExport {
|
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int refcount;
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void (*close)(NBDExport *exp);
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|
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BlockDriverState *bs; |
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char *name;
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off_t dev_offset; |
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off_t size; |
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uint32_t nbdflags; |
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QTAILQ_HEAD(, NBDClient) clients; |
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QTAILQ_ENTRY(NBDExport) next; |
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}; |
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|
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static QTAILQ_HEAD(, NBDExport) exports = QTAILQ_HEAD_INITIALIZER(exports);
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|
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struct NBDClient {
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int refcount;
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void (*close)(NBDClient *client);
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|
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NBDExport *exp; |
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int sock;
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|
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Coroutine *recv_coroutine; |
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|
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CoMutex send_lock; |
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Coroutine *send_coroutine; |
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|
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QTAILQ_ENTRY(NBDClient) next; |
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int nb_requests;
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bool closing;
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}; |
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|
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/* That's all folks */
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|
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ssize_t nbd_wr_sync(int fd, void *buffer, size_t size, bool do_read) |
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{
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size_t offset = 0;
|
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int err;
|
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|
| 131 |
if (qemu_in_coroutine()) {
|
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if (do_read) {
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return qemu_co_recv(fd, buffer, size);
|
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} else {
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return qemu_co_send(fd, buffer, size);
|
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} |
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} |
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|
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while (offset < size) {
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ssize_t len; |
| 141 |
|
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if (do_read) {
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len = qemu_recv(fd, buffer + offset, size - offset, 0);
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} else {
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len = send(fd, buffer + offset, size - offset, 0);
|
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} |
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|
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if (len < 0) { |
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err = socket_error(); |
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|
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/* recoverable error */
|
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if (err == EINTR || (offset > 0 && err == EAGAIN)) { |
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continue;
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} |
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|
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/* unrecoverable error */
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return -err;
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} |
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|
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/* eof */
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if (len == 0) { |
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break;
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} |
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|
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offset += len; |
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} |
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return offset;
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} |
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|
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static ssize_t read_sync(int fd, void *buffer, size_t size) |
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{
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/* Sockets are kept in blocking mode in the negotiation phase. After
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* that, a non-readable socket simply means that another thread stole
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* our request/reply. Synchronization is done with recv_coroutine, so
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* that this is coroutine-safe.
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*/
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return nbd_wr_sync(fd, buffer, size, true); |
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} |
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|
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static ssize_t write_sync(int fd, void *buffer, size_t size) |
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{
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int ret;
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do {
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/* For writes, we do expect the socket to be writable. */
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ret = nbd_wr_sync(fd, buffer, size, false);
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} while (ret == -EAGAIN);
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return ret;
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} |
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|
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/* Basic flow for negotiation
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|
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Server Client
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Negotiate
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|
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or
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Server Client
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Negotiate #1
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Option
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Negotiate #2
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|
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----
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|
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followed by
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|
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Server Client
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Request
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Response
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Request
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Response
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...
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...
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Request (type == 2)
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|
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*/
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|
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static int nbd_receive_options(NBDClient *client) |
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{
|
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int csock = client->sock;
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char name[256]; |
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uint32_t tmp, length; |
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uint64_t magic; |
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int rc;
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|
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/* Client sends:
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[ 0 .. 3] reserved (0)
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[ 4 .. 11] NBD_OPTS_MAGIC
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[12 .. 15] NBD_OPT_EXPORT_NAME
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[16 .. 19] length
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[20 .. xx] export name (length bytes)
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*/
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rc = -EINVAL; |
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if (read_sync(csock, &tmp, sizeof(tmp)) != sizeof(tmp)) { |
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LOG("read failed");
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goto fail;
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} |
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TRACE("Checking reserved");
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if (tmp != 0) { |
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LOG("Bad reserved received");
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goto fail;
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} |
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|
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if (read_sync(csock, &magic, sizeof(magic)) != sizeof(magic)) { |
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LOG("read failed");
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goto fail;
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} |
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TRACE("Checking reserved");
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if (magic != be64_to_cpu(NBD_OPTS_MAGIC)) {
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LOG("Bad magic received");
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goto fail;
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} |
| 254 |
|
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if (read_sync(csock, &tmp, sizeof(tmp)) != sizeof(tmp)) { |
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LOG("read failed");
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goto fail;
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} |
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TRACE("Checking option");
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if (tmp != be32_to_cpu(NBD_OPT_EXPORT_NAME)) {
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LOG("Bad option received");
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goto fail;
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} |
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|
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if (read_sync(csock, &length, sizeof(length)) != sizeof(length)) { |
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LOG("read failed");
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goto fail;
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} |
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TRACE("Checking length");
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length = be32_to_cpu(length); |
| 271 |
if (length > 255) { |
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LOG("Bad length received");
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goto fail;
|
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} |
| 275 |
if (read_sync(csock, name, length) != length) {
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LOG("read failed");
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goto fail;
|
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} |
| 279 |
name[length] = '\0';
|
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|
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client->exp = nbd_export_find(name); |
| 282 |
if (!client->exp) {
|
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LOG("export not found");
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goto fail;
|
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} |
| 286 |
|
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QTAILQ_INSERT_TAIL(&client->exp->clients, client, next); |
| 288 |
nbd_export_get(client->exp); |
| 289 |
|
| 290 |
TRACE("Option negotiation succeeded.");
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rc = 0;
|
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fail:
|
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return rc;
|
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} |
| 295 |
|
| 296 |
static int nbd_send_negotiate(NBDClient *client) |
| 297 |
{
|
| 298 |
int csock = client->sock;
|
| 299 |
char buf[8 + 8 + 8 + 128]; |
| 300 |
int rc;
|
| 301 |
const int myflags = (NBD_FLAG_HAS_FLAGS | NBD_FLAG_SEND_TRIM | |
| 302 |
NBD_FLAG_SEND_FLUSH | NBD_FLAG_SEND_FUA); |
| 303 |
|
| 304 |
/* Negotiation header without options:
|
| 305 |
[ 0 .. 7] passwd ("NBDMAGIC")
|
| 306 |
[ 8 .. 15] magic (NBD_CLIENT_MAGIC)
|
| 307 |
[16 .. 23] size
|
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[24 .. 25] server flags (0)
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| 309 |
[24 .. 27] export flags
|
| 310 |
[28 .. 151] reserved (0)
|
| 311 |
|
| 312 |
Negotiation header with options, part 1:
|
| 313 |
[ 0 .. 7] passwd ("NBDMAGIC")
|
| 314 |
[ 8 .. 15] magic (NBD_OPTS_MAGIC)
|
| 315 |
[16 .. 17] server flags (0)
|
| 316 |
|
| 317 |
part 2 (after options are sent):
|
| 318 |
[18 .. 25] size
|
| 319 |
[26 .. 27] export flags
|
| 320 |
[28 .. 151] reserved (0)
|
| 321 |
*/
|
| 322 |
|
| 323 |
qemu_set_block(csock); |
| 324 |
rc = -EINVAL; |
| 325 |
|
| 326 |
TRACE("Beginning negotiation.");
|
| 327 |
memset(buf, 0, sizeof(buf)); |
| 328 |
memcpy(buf, "NBDMAGIC", 8); |
| 329 |
if (client->exp) {
|
| 330 |
assert ((client->exp->nbdflags & ~65535) == 0); |
| 331 |
cpu_to_be64w((uint64_t*)(buf + 8), NBD_CLIENT_MAGIC);
|
| 332 |
cpu_to_be64w((uint64_t*)(buf + 16), client->exp->size);
|
| 333 |
cpu_to_be16w((uint16_t*)(buf + 26), client->exp->nbdflags | myflags);
|
| 334 |
} else {
|
| 335 |
cpu_to_be64w((uint64_t*)(buf + 8), NBD_OPTS_MAGIC);
|
| 336 |
} |
| 337 |
|
| 338 |
if (client->exp) {
|
| 339 |
if (write_sync(csock, buf, sizeof(buf)) != sizeof(buf)) { |
| 340 |
LOG("write failed");
|
| 341 |
goto fail;
|
| 342 |
} |
| 343 |
} else {
|
| 344 |
if (write_sync(csock, buf, 18) != 18) { |
| 345 |
LOG("write failed");
|
| 346 |
goto fail;
|
| 347 |
} |
| 348 |
rc = nbd_receive_options(client); |
| 349 |
if (rc < 0) { |
| 350 |
LOG("option negotiation failed");
|
| 351 |
goto fail;
|
| 352 |
} |
| 353 |
|
| 354 |
assert ((client->exp->nbdflags & ~65535) == 0); |
| 355 |
cpu_to_be64w((uint64_t*)(buf + 18), client->exp->size);
|
| 356 |
cpu_to_be16w((uint16_t*)(buf + 26), client->exp->nbdflags | myflags);
|
| 357 |
if (write_sync(csock, buf + 18, sizeof(buf) - 18) != sizeof(buf) - 18) { |
| 358 |
LOG("write failed");
|
| 359 |
goto fail;
|
| 360 |
} |
| 361 |
} |
| 362 |
|
| 363 |
TRACE("Negotiation succeeded.");
|
| 364 |
rc = 0;
|
| 365 |
fail:
|
| 366 |
qemu_set_nonblock(csock); |
| 367 |
return rc;
|
| 368 |
} |
| 369 |
|
| 370 |
int nbd_receive_negotiate(int csock, const char *name, uint32_t *flags, |
| 371 |
off_t *size, size_t *blocksize) |
| 372 |
{
|
| 373 |
char buf[256]; |
| 374 |
uint64_t magic, s; |
| 375 |
uint16_t tmp; |
| 376 |
int rc;
|
| 377 |
|
| 378 |
TRACE("Receiving negotiation.");
|
| 379 |
|
| 380 |
rc = -EINVAL; |
| 381 |
|
| 382 |
if (read_sync(csock, buf, 8) != 8) { |
| 383 |
LOG("read failed");
|
| 384 |
goto fail;
|
| 385 |
} |
| 386 |
|
| 387 |
buf[8] = '\0'; |
| 388 |
if (strlen(buf) == 0) { |
| 389 |
LOG("server connection closed");
|
| 390 |
goto fail;
|
| 391 |
} |
| 392 |
|
| 393 |
TRACE("Magic is %c%c%c%c%c%c%c%c",
|
| 394 |
qemu_isprint(buf[0]) ? buf[0] : '.', |
| 395 |
qemu_isprint(buf[1]) ? buf[1] : '.', |
| 396 |
qemu_isprint(buf[2]) ? buf[2] : '.', |
| 397 |
qemu_isprint(buf[3]) ? buf[3] : '.', |
| 398 |
qemu_isprint(buf[4]) ? buf[4] : '.', |
| 399 |
qemu_isprint(buf[5]) ? buf[5] : '.', |
| 400 |
qemu_isprint(buf[6]) ? buf[6] : '.', |
| 401 |
qemu_isprint(buf[7]) ? buf[7] : '.'); |
| 402 |
|
| 403 |
if (memcmp(buf, "NBDMAGIC", 8) != 0) { |
| 404 |
LOG("Invalid magic received");
|
| 405 |
goto fail;
|
| 406 |
} |
| 407 |
|
| 408 |
if (read_sync(csock, &magic, sizeof(magic)) != sizeof(magic)) { |
| 409 |
LOG("read failed");
|
| 410 |
goto fail;
|
| 411 |
} |
| 412 |
magic = be64_to_cpu(magic); |
| 413 |
TRACE("Magic is 0x%" PRIx64, magic);
|
| 414 |
|
| 415 |
if (name) {
|
| 416 |
uint32_t reserved = 0;
|
| 417 |
uint32_t opt; |
| 418 |
uint32_t namesize; |
| 419 |
|
| 420 |
TRACE("Checking magic (opts_magic)");
|
| 421 |
if (magic != NBD_OPTS_MAGIC) {
|
| 422 |
LOG("Bad magic received");
|
| 423 |
goto fail;
|
| 424 |
} |
| 425 |
if (read_sync(csock, &tmp, sizeof(tmp)) != sizeof(tmp)) { |
| 426 |
LOG("flags read failed");
|
| 427 |
goto fail;
|
| 428 |
} |
| 429 |
*flags = be16_to_cpu(tmp) << 16;
|
| 430 |
/* reserved for future use */
|
| 431 |
if (write_sync(csock, &reserved, sizeof(reserved)) != |
| 432 |
sizeof(reserved)) {
|
| 433 |
LOG("write failed (reserved)");
|
| 434 |
goto fail;
|
| 435 |
} |
| 436 |
/* write the export name */
|
| 437 |
magic = cpu_to_be64(magic); |
| 438 |
if (write_sync(csock, &magic, sizeof(magic)) != sizeof(magic)) { |
| 439 |
LOG("write failed (magic)");
|
| 440 |
goto fail;
|
| 441 |
} |
| 442 |
opt = cpu_to_be32(NBD_OPT_EXPORT_NAME); |
| 443 |
if (write_sync(csock, &opt, sizeof(opt)) != sizeof(opt)) { |
| 444 |
LOG("write failed (opt)");
|
| 445 |
goto fail;
|
| 446 |
} |
| 447 |
namesize = cpu_to_be32(strlen(name)); |
| 448 |
if (write_sync(csock, &namesize, sizeof(namesize)) != |
| 449 |
sizeof(namesize)) {
|
| 450 |
LOG("write failed (namesize)");
|
| 451 |
goto fail;
|
| 452 |
} |
| 453 |
if (write_sync(csock, (char*)name, strlen(name)) != strlen(name)) { |
| 454 |
LOG("write failed (name)");
|
| 455 |
goto fail;
|
| 456 |
} |
| 457 |
} else {
|
| 458 |
TRACE("Checking magic (cli_magic)");
|
| 459 |
|
| 460 |
if (magic != NBD_CLIENT_MAGIC) {
|
| 461 |
LOG("Bad magic received");
|
| 462 |
goto fail;
|
| 463 |
} |
| 464 |
} |
| 465 |
|
| 466 |
if (read_sync(csock, &s, sizeof(s)) != sizeof(s)) { |
| 467 |
LOG("read failed");
|
| 468 |
goto fail;
|
| 469 |
} |
| 470 |
*size = be64_to_cpu(s); |
| 471 |
*blocksize = 1024;
|
| 472 |
TRACE("Size is %" PRIu64, *size);
|
| 473 |
|
| 474 |
if (!name) {
|
| 475 |
if (read_sync(csock, flags, sizeof(*flags)) != sizeof(*flags)) { |
| 476 |
LOG("read failed (flags)");
|
| 477 |
goto fail;
|
| 478 |
} |
| 479 |
*flags = be32_to_cpup(flags); |
| 480 |
} else {
|
| 481 |
if (read_sync(csock, &tmp, sizeof(tmp)) != sizeof(tmp)) { |
| 482 |
LOG("read failed (tmp)");
|
| 483 |
goto fail;
|
| 484 |
} |
| 485 |
*flags |= be32_to_cpu(tmp); |
| 486 |
} |
| 487 |
if (read_sync(csock, &buf, 124) != 124) { |
| 488 |
LOG("read failed (buf)");
|
| 489 |
goto fail;
|
| 490 |
} |
| 491 |
rc = 0;
|
| 492 |
|
| 493 |
fail:
|
| 494 |
return rc;
|
| 495 |
} |
| 496 |
|
| 497 |
#ifdef __linux__
|
| 498 |
int nbd_init(int fd, int csock, uint32_t flags, off_t size, size_t blocksize) |
| 499 |
{
|
| 500 |
TRACE("Setting NBD socket");
|
| 501 |
|
| 502 |
if (ioctl(fd, NBD_SET_SOCK, csock) < 0) { |
| 503 |
int serrno = errno;
|
| 504 |
LOG("Failed to set NBD socket");
|
| 505 |
return -serrno;
|
| 506 |
} |
| 507 |
|
| 508 |
TRACE("Setting block size to %lu", (unsigned long)blocksize); |
| 509 |
|
| 510 |
if (ioctl(fd, NBD_SET_BLKSIZE, blocksize) < 0) { |
| 511 |
int serrno = errno;
|
| 512 |
LOG("Failed setting NBD block size");
|
| 513 |
return -serrno;
|
| 514 |
} |
| 515 |
|
| 516 |
TRACE("Setting size to %zd block(s)", (size_t)(size / blocksize));
|
| 517 |
|
| 518 |
if (ioctl(fd, NBD_SET_SIZE_BLOCKS, size / blocksize) < 0) { |
| 519 |
int serrno = errno;
|
| 520 |
LOG("Failed setting size (in blocks)");
|
| 521 |
return -serrno;
|
| 522 |
} |
| 523 |
|
| 524 |
if (ioctl(fd, NBD_SET_FLAGS, flags) < 0) { |
| 525 |
if (errno == ENOTTY) {
|
| 526 |
int read_only = (flags & NBD_FLAG_READ_ONLY) != 0; |
| 527 |
TRACE("Setting readonly attribute");
|
| 528 |
|
| 529 |
if (ioctl(fd, BLKROSET, (unsigned long) &read_only) < 0) { |
| 530 |
int serrno = errno;
|
| 531 |
LOG("Failed setting read-only attribute");
|
| 532 |
return -serrno;
|
| 533 |
} |
| 534 |
} else {
|
| 535 |
int serrno = errno;
|
| 536 |
LOG("Failed setting flags");
|
| 537 |
return -serrno;
|
| 538 |
} |
| 539 |
} |
| 540 |
|
| 541 |
TRACE("Negotiation ended");
|
| 542 |
|
| 543 |
return 0; |
| 544 |
} |
| 545 |
|
| 546 |
int nbd_disconnect(int fd) |
| 547 |
{
|
| 548 |
ioctl(fd, NBD_CLEAR_QUE); |
| 549 |
ioctl(fd, NBD_DISCONNECT); |
| 550 |
ioctl(fd, NBD_CLEAR_SOCK); |
| 551 |
return 0; |
| 552 |
} |
| 553 |
|
| 554 |
int nbd_client(int fd) |
| 555 |
{
|
| 556 |
int ret;
|
| 557 |
int serrno;
|
| 558 |
|
| 559 |
TRACE("Doing NBD loop");
|
| 560 |
|
| 561 |
ret = ioctl(fd, NBD_DO_IT); |
| 562 |
if (ret < 0 && errno == EPIPE) { |
| 563 |
/* NBD_DO_IT normally returns EPIPE when someone has disconnected
|
| 564 |
* the socket via NBD_DISCONNECT. We do not want to return 1 in
|
| 565 |
* that case.
|
| 566 |
*/
|
| 567 |
ret = 0;
|
| 568 |
} |
| 569 |
serrno = errno; |
| 570 |
|
| 571 |
TRACE("NBD loop returned %d: %s", ret, strerror(serrno));
|
| 572 |
|
| 573 |
TRACE("Clearing NBD queue");
|
| 574 |
ioctl(fd, NBD_CLEAR_QUE); |
| 575 |
|
| 576 |
TRACE("Clearing NBD socket");
|
| 577 |
ioctl(fd, NBD_CLEAR_SOCK); |
| 578 |
|
| 579 |
errno = serrno; |
| 580 |
return ret;
|
| 581 |
} |
| 582 |
#else
|
| 583 |
int nbd_init(int fd, int csock, uint32_t flags, off_t size, size_t blocksize) |
| 584 |
{
|
| 585 |
return -ENOTSUP;
|
| 586 |
} |
| 587 |
|
| 588 |
int nbd_disconnect(int fd) |
| 589 |
{
|
| 590 |
return -ENOTSUP;
|
| 591 |
} |
| 592 |
|
| 593 |
int nbd_client(int fd) |
| 594 |
{
|
| 595 |
return -ENOTSUP;
|
| 596 |
} |
| 597 |
#endif
|
| 598 |
|
| 599 |
ssize_t nbd_send_request(int csock, struct nbd_request *request) |
| 600 |
{
|
| 601 |
uint8_t buf[NBD_REQUEST_SIZE]; |
| 602 |
ssize_t ret; |
| 603 |
|
| 604 |
cpu_to_be32w((uint32_t*)buf, NBD_REQUEST_MAGIC); |
| 605 |
cpu_to_be32w((uint32_t*)(buf + 4), request->type);
|
| 606 |
cpu_to_be64w((uint64_t*)(buf + 8), request->handle);
|
| 607 |
cpu_to_be64w((uint64_t*)(buf + 16), request->from);
|
| 608 |
cpu_to_be32w((uint32_t*)(buf + 24), request->len);
|
| 609 |
|
| 610 |
TRACE("Sending request to client: "
|
| 611 |
"{ .from = %" PRIu64", .len = %u, .handle = %" PRIu64", .type=%i}", |
| 612 |
request->from, request->len, request->handle, request->type); |
| 613 |
|
| 614 |
ret = write_sync(csock, buf, sizeof(buf));
|
| 615 |
if (ret < 0) { |
| 616 |
return ret;
|
| 617 |
} |
| 618 |
|
| 619 |
if (ret != sizeof(buf)) { |
| 620 |
LOG("writing to socket failed");
|
| 621 |
return -EINVAL;
|
| 622 |
} |
| 623 |
return 0; |
| 624 |
} |
| 625 |
|
| 626 |
static ssize_t nbd_receive_request(int csock, struct nbd_request *request) |
| 627 |
{
|
| 628 |
uint8_t buf[NBD_REQUEST_SIZE]; |
| 629 |
uint32_t magic; |
| 630 |
ssize_t ret; |
| 631 |
|
| 632 |
ret = read_sync(csock, buf, sizeof(buf));
|
| 633 |
if (ret < 0) { |
| 634 |
return ret;
|
| 635 |
} |
| 636 |
|
| 637 |
if (ret != sizeof(buf)) { |
| 638 |
LOG("read failed");
|
| 639 |
return -EINVAL;
|
| 640 |
} |
| 641 |
|
| 642 |
/* Request
|
| 643 |
[ 0 .. 3] magic (NBD_REQUEST_MAGIC)
|
| 644 |
[ 4 .. 7] type (0 == READ, 1 == WRITE)
|
| 645 |
[ 8 .. 15] handle
|
| 646 |
[16 .. 23] from
|
| 647 |
[24 .. 27] len
|
| 648 |
*/
|
| 649 |
|
| 650 |
magic = be32_to_cpup((uint32_t*)buf); |
| 651 |
request->type = be32_to_cpup((uint32_t*)(buf + 4));
|
| 652 |
request->handle = be64_to_cpup((uint64_t*)(buf + 8));
|
| 653 |
request->from = be64_to_cpup((uint64_t*)(buf + 16));
|
| 654 |
request->len = be32_to_cpup((uint32_t*)(buf + 24));
|
| 655 |
|
| 656 |
TRACE("Got request: "
|
| 657 |
"{ magic = 0x%x, .type = %d, from = %" PRIu64" , len = %u }", |
| 658 |
magic, request->type, request->from, request->len); |
| 659 |
|
| 660 |
if (magic != NBD_REQUEST_MAGIC) {
|
| 661 |
LOG("invalid magic (got 0x%x)", magic);
|
| 662 |
return -EINVAL;
|
| 663 |
} |
| 664 |
return 0; |
| 665 |
} |
| 666 |
|
| 667 |
ssize_t nbd_receive_reply(int csock, struct nbd_reply *reply) |
| 668 |
{
|
| 669 |
uint8_t buf[NBD_REPLY_SIZE]; |
| 670 |
uint32_t magic; |
| 671 |
ssize_t ret; |
| 672 |
|
| 673 |
ret = read_sync(csock, buf, sizeof(buf));
|
| 674 |
if (ret < 0) { |
| 675 |
return ret;
|
| 676 |
} |
| 677 |
|
| 678 |
if (ret != sizeof(buf)) { |
| 679 |
LOG("read failed");
|
| 680 |
return -EINVAL;
|
| 681 |
} |
| 682 |
|
| 683 |
/* Reply
|
| 684 |
[ 0 .. 3] magic (NBD_REPLY_MAGIC)
|
| 685 |
[ 4 .. 7] error (0 == no error)
|
| 686 |
[ 7 .. 15] handle
|
| 687 |
*/
|
| 688 |
|
| 689 |
magic = be32_to_cpup((uint32_t*)buf); |
| 690 |
reply->error = be32_to_cpup((uint32_t*)(buf + 4));
|
| 691 |
reply->handle = be64_to_cpup((uint64_t*)(buf + 8));
|
| 692 |
|
| 693 |
TRACE("Got reply: "
|
| 694 |
"{ magic = 0x%x, .error = %d, handle = %" PRIu64" }", |
| 695 |
magic, reply->error, reply->handle); |
| 696 |
|
| 697 |
if (magic != NBD_REPLY_MAGIC) {
|
| 698 |
LOG("invalid magic (got 0x%x)", magic);
|
| 699 |
return -EINVAL;
|
| 700 |
} |
| 701 |
return 0; |
| 702 |
} |
| 703 |
|
| 704 |
static ssize_t nbd_send_reply(int csock, struct nbd_reply *reply) |
| 705 |
{
|
| 706 |
uint8_t buf[NBD_REPLY_SIZE]; |
| 707 |
ssize_t ret; |
| 708 |
|
| 709 |
/* Reply
|
| 710 |
[ 0 .. 3] magic (NBD_REPLY_MAGIC)
|
| 711 |
[ 4 .. 7] error (0 == no error)
|
| 712 |
[ 7 .. 15] handle
|
| 713 |
*/
|
| 714 |
cpu_to_be32w((uint32_t*)buf, NBD_REPLY_MAGIC); |
| 715 |
cpu_to_be32w((uint32_t*)(buf + 4), reply->error);
|
| 716 |
cpu_to_be64w((uint64_t*)(buf + 8), reply->handle);
|
| 717 |
|
| 718 |
TRACE("Sending response to client");
|
| 719 |
|
| 720 |
ret = write_sync(csock, buf, sizeof(buf));
|
| 721 |
if (ret < 0) { |
| 722 |
return ret;
|
| 723 |
} |
| 724 |
|
| 725 |
if (ret != sizeof(buf)) { |
| 726 |
LOG("writing to socket failed");
|
| 727 |
return -EINVAL;
|
| 728 |
} |
| 729 |
return 0; |
| 730 |
} |
| 731 |
|
| 732 |
#define MAX_NBD_REQUESTS 16 |
| 733 |
|
| 734 |
void nbd_client_get(NBDClient *client)
|
| 735 |
{
|
| 736 |
client->refcount++; |
| 737 |
} |
| 738 |
|
| 739 |
void nbd_client_put(NBDClient *client)
|
| 740 |
{
|
| 741 |
if (--client->refcount == 0) { |
| 742 |
/* The last reference should be dropped by client->close,
|
| 743 |
* which is called by nbd_client_close.
|
| 744 |
*/
|
| 745 |
assert(client->closing); |
| 746 |
|
| 747 |
qemu_set_fd_handler2(client->sock, NULL, NULL, NULL, NULL); |
| 748 |
close(client->sock); |
| 749 |
client->sock = -1;
|
| 750 |
if (client->exp) {
|
| 751 |
QTAILQ_REMOVE(&client->exp->clients, client, next); |
| 752 |
nbd_export_put(client->exp); |
| 753 |
} |
| 754 |
g_free(client); |
| 755 |
} |
| 756 |
} |
| 757 |
|
| 758 |
void nbd_client_close(NBDClient *client)
|
| 759 |
{
|
| 760 |
if (client->closing) {
|
| 761 |
return;
|
| 762 |
} |
| 763 |
|
| 764 |
client->closing = true;
|
| 765 |
|
| 766 |
/* Force requests to finish. They will drop their own references,
|
| 767 |
* then we'll close the socket and free the NBDClient.
|
| 768 |
*/
|
| 769 |
shutdown(client->sock, 2);
|
| 770 |
|
| 771 |
/* Also tell the client, so that they release their reference. */
|
| 772 |
if (client->close) {
|
| 773 |
client->close(client); |
| 774 |
} |
| 775 |
} |
| 776 |
|
| 777 |
static NBDRequest *nbd_request_get(NBDClient *client)
|
| 778 |
{
|
| 779 |
NBDRequest *req; |
| 780 |
|
| 781 |
assert(client->nb_requests <= MAX_NBD_REQUESTS - 1);
|
| 782 |
client->nb_requests++; |
| 783 |
|
| 784 |
req = g_slice_new0(NBDRequest); |
| 785 |
nbd_client_get(client); |
| 786 |
req->client = client; |
| 787 |
return req;
|
| 788 |
} |
| 789 |
|
| 790 |
static void nbd_request_put(NBDRequest *req) |
| 791 |
{
|
| 792 |
NBDClient *client = req->client; |
| 793 |
|
| 794 |
if (req->data) {
|
| 795 |
qemu_vfree(req->data); |
| 796 |
} |
| 797 |
g_slice_free(NBDRequest, req); |
| 798 |
|
| 799 |
if (client->nb_requests-- == MAX_NBD_REQUESTS) {
|
| 800 |
qemu_notify_event(); |
| 801 |
} |
| 802 |
nbd_client_put(client); |
| 803 |
} |
| 804 |
|
| 805 |
NBDExport *nbd_export_new(BlockDriverState *bs, off_t dev_offset, |
| 806 |
off_t size, uint32_t nbdflags, |
| 807 |
void (*close)(NBDExport *))
|
| 808 |
{
|
| 809 |
NBDExport *exp = g_malloc0(sizeof(NBDExport));
|
| 810 |
exp->refcount = 1;
|
| 811 |
QTAILQ_INIT(&exp->clients); |
| 812 |
exp->bs = bs; |
| 813 |
exp->dev_offset = dev_offset; |
| 814 |
exp->nbdflags = nbdflags; |
| 815 |
exp->size = size == -1 ? bdrv_getlength(bs) : size;
|
| 816 |
exp->close = close; |
| 817 |
bdrv_ref(bs); |
| 818 |
return exp;
|
| 819 |
} |
| 820 |
|
| 821 |
NBDExport *nbd_export_find(const char *name) |
| 822 |
{
|
| 823 |
NBDExport *exp; |
| 824 |
QTAILQ_FOREACH(exp, &exports, next) {
|
| 825 |
if (strcmp(name, exp->name) == 0) { |
| 826 |
return exp;
|
| 827 |
} |
| 828 |
} |
| 829 |
|
| 830 |
return NULL; |
| 831 |
} |
| 832 |
|
| 833 |
void nbd_export_set_name(NBDExport *exp, const char *name) |
| 834 |
{
|
| 835 |
if (exp->name == name) {
|
| 836 |
return;
|
| 837 |
} |
| 838 |
|
| 839 |
nbd_export_get(exp); |
| 840 |
if (exp->name != NULL) { |
| 841 |
g_free(exp->name); |
| 842 |
exp->name = NULL;
|
| 843 |
QTAILQ_REMOVE(&exports, exp, next); |
| 844 |
nbd_export_put(exp); |
| 845 |
} |
| 846 |
if (name != NULL) { |
| 847 |
nbd_export_get(exp); |
| 848 |
exp->name = g_strdup(name); |
| 849 |
QTAILQ_INSERT_TAIL(&exports, exp, next); |
| 850 |
} |
| 851 |
nbd_export_put(exp); |
| 852 |
} |
| 853 |
|
| 854 |
void nbd_export_close(NBDExport *exp)
|
| 855 |
{
|
| 856 |
NBDClient *client, *next; |
| 857 |
|
| 858 |
nbd_export_get(exp); |
| 859 |
QTAILQ_FOREACH_SAFE(client, &exp->clients, next, next) {
|
| 860 |
nbd_client_close(client); |
| 861 |
} |
| 862 |
nbd_export_set_name(exp, NULL);
|
| 863 |
nbd_export_put(exp); |
| 864 |
if (exp->bs) {
|
| 865 |
bdrv_unref(exp->bs); |
| 866 |
exp->bs = NULL;
|
| 867 |
} |
| 868 |
} |
| 869 |
|
| 870 |
void nbd_export_get(NBDExport *exp)
|
| 871 |
{
|
| 872 |
assert(exp->refcount > 0);
|
| 873 |
exp->refcount++; |
| 874 |
} |
| 875 |
|
| 876 |
void nbd_export_put(NBDExport *exp)
|
| 877 |
{
|
| 878 |
assert(exp->refcount > 0);
|
| 879 |
if (exp->refcount == 1) { |
| 880 |
nbd_export_close(exp); |
| 881 |
} |
| 882 |
|
| 883 |
if (--exp->refcount == 0) { |
| 884 |
assert(exp->name == NULL);
|
| 885 |
|
| 886 |
if (exp->close) {
|
| 887 |
exp->close(exp); |
| 888 |
} |
| 889 |
|
| 890 |
g_free(exp); |
| 891 |
} |
| 892 |
} |
| 893 |
|
| 894 |
BlockDriverState *nbd_export_get_blockdev(NBDExport *exp) |
| 895 |
{
|
| 896 |
return exp->bs;
|
| 897 |
} |
| 898 |
|
| 899 |
void nbd_export_close_all(void) |
| 900 |
{
|
| 901 |
NBDExport *exp, *next; |
| 902 |
|
| 903 |
QTAILQ_FOREACH_SAFE(exp, &exports, next, next) {
|
| 904 |
nbd_export_close(exp); |
| 905 |
} |
| 906 |
} |
| 907 |
|
| 908 |
static int nbd_can_read(void *opaque); |
| 909 |
static void nbd_read(void *opaque); |
| 910 |
static void nbd_restart_write(void *opaque); |
| 911 |
|
| 912 |
static ssize_t nbd_co_send_reply(NBDRequest *req, struct nbd_reply *reply, |
| 913 |
int len)
|
| 914 |
{
|
| 915 |
NBDClient *client = req->client; |
| 916 |
int csock = client->sock;
|
| 917 |
ssize_t rc, ret; |
| 918 |
|
| 919 |
qemu_co_mutex_lock(&client->send_lock); |
| 920 |
qemu_set_fd_handler2(csock, nbd_can_read, nbd_read, |
| 921 |
nbd_restart_write, client); |
| 922 |
client->send_coroutine = qemu_coroutine_self(); |
| 923 |
|
| 924 |
if (!len) {
|
| 925 |
rc = nbd_send_reply(csock, reply); |
| 926 |
} else {
|
| 927 |
socket_set_cork(csock, 1);
|
| 928 |
rc = nbd_send_reply(csock, reply); |
| 929 |
if (rc >= 0) { |
| 930 |
ret = qemu_co_send(csock, req->data, len); |
| 931 |
if (ret != len) {
|
| 932 |
rc = -EIO; |
| 933 |
} |
| 934 |
} |
| 935 |
socket_set_cork(csock, 0);
|
| 936 |
} |
| 937 |
|
| 938 |
client->send_coroutine = NULL;
|
| 939 |
qemu_set_fd_handler2(csock, nbd_can_read, nbd_read, NULL, client);
|
| 940 |
qemu_co_mutex_unlock(&client->send_lock); |
| 941 |
return rc;
|
| 942 |
} |
| 943 |
|
| 944 |
static ssize_t nbd_co_receive_request(NBDRequest *req, struct nbd_request *request) |
| 945 |
{
|
| 946 |
NBDClient *client = req->client; |
| 947 |
int csock = client->sock;
|
| 948 |
uint32_t command; |
| 949 |
ssize_t rc; |
| 950 |
|
| 951 |
client->recv_coroutine = qemu_coroutine_self(); |
| 952 |
rc = nbd_receive_request(csock, request); |
| 953 |
if (rc < 0) { |
| 954 |
if (rc != -EAGAIN) {
|
| 955 |
rc = -EIO; |
| 956 |
} |
| 957 |
goto out;
|
| 958 |
} |
| 959 |
|
| 960 |
if (request->len > NBD_MAX_BUFFER_SIZE) {
|
| 961 |
LOG("len (%u) is larger than max len (%u)",
|
| 962 |
request->len, NBD_MAX_BUFFER_SIZE); |
| 963 |
rc = -EINVAL; |
| 964 |
goto out;
|
| 965 |
} |
| 966 |
|
| 967 |
if ((request->from + request->len) < request->from) {
|
| 968 |
LOG("integer overflow detected! "
|
| 969 |
"you're probably being attacked");
|
| 970 |
rc = -EINVAL; |
| 971 |
goto out;
|
| 972 |
} |
| 973 |
|
| 974 |
TRACE("Decoding type");
|
| 975 |
|
| 976 |
command = request->type & NBD_CMD_MASK_COMMAND; |
| 977 |
if (command == NBD_CMD_READ || command == NBD_CMD_WRITE) {
|
| 978 |
req->data = qemu_blockalign(client->exp->bs, request->len); |
| 979 |
} |
| 980 |
if (command == NBD_CMD_WRITE) {
|
| 981 |
TRACE("Reading %u byte(s)", request->len);
|
| 982 |
|
| 983 |
if (qemu_co_recv(csock, req->data, request->len) != request->len) {
|
| 984 |
LOG("reading from socket failed");
|
| 985 |
rc = -EIO; |
| 986 |
goto out;
|
| 987 |
} |
| 988 |
} |
| 989 |
rc = 0;
|
| 990 |
|
| 991 |
out:
|
| 992 |
client->recv_coroutine = NULL;
|
| 993 |
return rc;
|
| 994 |
} |
| 995 |
|
| 996 |
static void nbd_trip(void *opaque) |
| 997 |
{
|
| 998 |
NBDClient *client = opaque; |
| 999 |
NBDExport *exp = client->exp; |
| 1000 |
NBDRequest *req; |
| 1001 |
struct nbd_request request;
|
| 1002 |
struct nbd_reply reply;
|
| 1003 |
ssize_t ret; |
| 1004 |
|
| 1005 |
TRACE("Reading request.");
|
| 1006 |
if (client->closing) {
|
| 1007 |
return;
|
| 1008 |
} |
| 1009 |
|
| 1010 |
req = nbd_request_get(client); |
| 1011 |
ret = nbd_co_receive_request(req, &request); |
| 1012 |
if (ret == -EAGAIN) {
|
| 1013 |
goto done;
|
| 1014 |
} |
| 1015 |
if (ret == -EIO) {
|
| 1016 |
goto out;
|
| 1017 |
} |
| 1018 |
|
| 1019 |
reply.handle = request.handle; |
| 1020 |
reply.error = 0;
|
| 1021 |
|
| 1022 |
if (ret < 0) { |
| 1023 |
reply.error = -ret; |
| 1024 |
goto error_reply;
|
| 1025 |
} |
| 1026 |
|
| 1027 |
if ((request.from + request.len) > exp->size) {
|
| 1028 |
LOG("From: %" PRIu64 ", Len: %u, Size: %" PRIu64 |
| 1029 |
", Offset: %" PRIu64 "\n", |
| 1030 |
request.from, request.len, |
| 1031 |
(uint64_t)exp->size, (uint64_t)exp->dev_offset); |
| 1032 |
LOG("requested operation past EOF--bad client?");
|
| 1033 |
goto invalid_request;
|
| 1034 |
} |
| 1035 |
|
| 1036 |
switch (request.type & NBD_CMD_MASK_COMMAND) {
|
| 1037 |
case NBD_CMD_READ:
|
| 1038 |
TRACE("Request type is READ");
|
| 1039 |
|
| 1040 |
if (request.type & NBD_CMD_FLAG_FUA) {
|
| 1041 |
ret = bdrv_co_flush(exp->bs); |
| 1042 |
if (ret < 0) { |
| 1043 |
LOG("flush failed");
|
| 1044 |
reply.error = -ret; |
| 1045 |
goto error_reply;
|
| 1046 |
} |
| 1047 |
} |
| 1048 |
|
| 1049 |
ret = bdrv_read(exp->bs, (request.from + exp->dev_offset) / 512,
|
| 1050 |
req->data, request.len / 512);
|
| 1051 |
if (ret < 0) { |
| 1052 |
LOG("reading from file failed");
|
| 1053 |
reply.error = -ret; |
| 1054 |
goto error_reply;
|
| 1055 |
} |
| 1056 |
|
| 1057 |
TRACE("Read %u byte(s)", request.len);
|
| 1058 |
if (nbd_co_send_reply(req, &reply, request.len) < 0) |
| 1059 |
goto out;
|
| 1060 |
break;
|
| 1061 |
case NBD_CMD_WRITE:
|
| 1062 |
TRACE("Request type is WRITE");
|
| 1063 |
|
| 1064 |
if (exp->nbdflags & NBD_FLAG_READ_ONLY) {
|
| 1065 |
TRACE("Server is read-only, return error");
|
| 1066 |
reply.error = EROFS; |
| 1067 |
goto error_reply;
|
| 1068 |
} |
| 1069 |
|
| 1070 |
TRACE("Writing to device");
|
| 1071 |
|
| 1072 |
ret = bdrv_write(exp->bs, (request.from + exp->dev_offset) / 512,
|
| 1073 |
req->data, request.len / 512);
|
| 1074 |
if (ret < 0) { |
| 1075 |
LOG("writing to file failed");
|
| 1076 |
reply.error = -ret; |
| 1077 |
goto error_reply;
|
| 1078 |
} |
| 1079 |
|
| 1080 |
if (request.type & NBD_CMD_FLAG_FUA) {
|
| 1081 |
ret = bdrv_co_flush(exp->bs); |
| 1082 |
if (ret < 0) { |
| 1083 |
LOG("flush failed");
|
| 1084 |
reply.error = -ret; |
| 1085 |
goto error_reply;
|
| 1086 |
} |
| 1087 |
} |
| 1088 |
|
| 1089 |
if (nbd_co_send_reply(req, &reply, 0) < 0) { |
| 1090 |
goto out;
|
| 1091 |
} |
| 1092 |
break;
|
| 1093 |
case NBD_CMD_DISC:
|
| 1094 |
TRACE("Request type is DISCONNECT");
|
| 1095 |
errno = 0;
|
| 1096 |
goto out;
|
| 1097 |
case NBD_CMD_FLUSH:
|
| 1098 |
TRACE("Request type is FLUSH");
|
| 1099 |
|
| 1100 |
ret = bdrv_co_flush(exp->bs); |
| 1101 |
if (ret < 0) { |
| 1102 |
LOG("flush failed");
|
| 1103 |
reply.error = -ret; |
| 1104 |
} |
| 1105 |
if (nbd_co_send_reply(req, &reply, 0) < 0) { |
| 1106 |
goto out;
|
| 1107 |
} |
| 1108 |
break;
|
| 1109 |
case NBD_CMD_TRIM:
|
| 1110 |
TRACE("Request type is TRIM");
|
| 1111 |
ret = bdrv_co_discard(exp->bs, (request.from + exp->dev_offset) / 512,
|
| 1112 |
request.len / 512);
|
| 1113 |
if (ret < 0) { |
| 1114 |
LOG("discard failed");
|
| 1115 |
reply.error = -ret; |
| 1116 |
} |
| 1117 |
if (nbd_co_send_reply(req, &reply, 0) < 0) { |
| 1118 |
goto out;
|
| 1119 |
} |
| 1120 |
break;
|
| 1121 |
default:
|
| 1122 |
LOG("invalid request type (%u) received", request.type);
|
| 1123 |
invalid_request:
|
| 1124 |
reply.error = -EINVAL; |
| 1125 |
error_reply:
|
| 1126 |
if (nbd_co_send_reply(req, &reply, 0) < 0) { |
| 1127 |
goto out;
|
| 1128 |
} |
| 1129 |
break;
|
| 1130 |
} |
| 1131 |
|
| 1132 |
TRACE("Request/Reply complete");
|
| 1133 |
|
| 1134 |
done:
|
| 1135 |
nbd_request_put(req); |
| 1136 |
return;
|
| 1137 |
|
| 1138 |
out:
|
| 1139 |
nbd_request_put(req); |
| 1140 |
nbd_client_close(client); |
| 1141 |
} |
| 1142 |
|
| 1143 |
static int nbd_can_read(void *opaque) |
| 1144 |
{
|
| 1145 |
NBDClient *client = opaque; |
| 1146 |
|
| 1147 |
return client->recv_coroutine || client->nb_requests < MAX_NBD_REQUESTS;
|
| 1148 |
} |
| 1149 |
|
| 1150 |
static void nbd_read(void *opaque) |
| 1151 |
{
|
| 1152 |
NBDClient *client = opaque; |
| 1153 |
|
| 1154 |
if (client->recv_coroutine) {
|
| 1155 |
qemu_coroutine_enter(client->recv_coroutine, NULL);
|
| 1156 |
} else {
|
| 1157 |
qemu_coroutine_enter(qemu_coroutine_create(nbd_trip), client); |
| 1158 |
} |
| 1159 |
} |
| 1160 |
|
| 1161 |
static void nbd_restart_write(void *opaque) |
| 1162 |
{
|
| 1163 |
NBDClient *client = opaque; |
| 1164 |
|
| 1165 |
qemu_coroutine_enter(client->send_coroutine, NULL);
|
| 1166 |
} |
| 1167 |
|
| 1168 |
NBDClient *nbd_client_new(NBDExport *exp, int csock,
|
| 1169 |
void (*close)(NBDClient *))
|
| 1170 |
{
|
| 1171 |
NBDClient *client; |
| 1172 |
client = g_malloc0(sizeof(NBDClient));
|
| 1173 |
client->refcount = 1;
|
| 1174 |
client->exp = exp; |
| 1175 |
client->sock = csock; |
| 1176 |
if (nbd_send_negotiate(client) < 0) { |
| 1177 |
g_free(client); |
| 1178 |
return NULL; |
| 1179 |
} |
| 1180 |
client->close = close; |
| 1181 |
qemu_co_mutex_init(&client->send_lock); |
| 1182 |
qemu_set_fd_handler2(csock, nbd_can_read, nbd_read, NULL, client);
|
| 1183 |
|
| 1184 |
if (exp) {
|
| 1185 |
QTAILQ_INSERT_TAIL(&exp->clients, client, next); |
| 1186 |
nbd_export_get(exp); |
| 1187 |
} |
| 1188 |
return client;
|
| 1189 |
} |