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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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* 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 "nbd.h" |
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#include "block.h" |
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#include "qemu-coroutine.h" |
23 |
|
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#include <errno.h> |
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#include <string.h> |
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#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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#ifdef __linux__
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#include <linux/fs.h> |
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#endif
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#include "qemu_socket.h" |
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#include "qemu-queue.h" |
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//#define DEBUG_NBD
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#ifdef DEBUG_NBD
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#define TRACE(msg, ...) do { \ |
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LOG(msg, ## __VA_ARGS__); \ |
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} while(0) |
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#else
|
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#define TRACE(msg, ...) \
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do { } while (0) |
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#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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/* 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) |
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#define NBD_REQUEST_MAGIC 0x25609513 |
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#define NBD_REPLY_MAGIC 0x67446698 |
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#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) |
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#define NBD_SET_BLKSIZE _IO(0xab, 1) |
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#define NBD_SET_SIZE _IO(0xab, 2) |
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#define NBD_DO_IT _IO(0xab, 3) |
71 |
#define NBD_CLEAR_SOCK _IO(0xab, 4) |
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#define NBD_CLEAR_QUE _IO(0xab, 5) |
73 |
#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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/* Definitions for opaque data types */
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typedef struct NBDRequest NBDRequest; |
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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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struct NBDExport {
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BlockDriverState *bs; |
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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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QSIMPLEQ_HEAD(, NBDRequest) requests; |
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}; |
98 |
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struct NBDClient {
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int refcount;
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void (*close)(NBDClient *client);
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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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int nb_requests;
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}; |
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/* That's all folks */
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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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|
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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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} |
128 |
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while (offset < size) {
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ssize_t len; |
131 |
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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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} |
137 |
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if (len < 0) { |
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err = socket_error(); |
140 |
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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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} |
145 |
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/* unrecoverable error */
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return -err;
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} |
149 |
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/* eof */
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if (len == 0) { |
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break;
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} |
154 |
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offset += len; |
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} |
157 |
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return offset;
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} |
160 |
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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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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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} |
180 |
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static void combine_addr(char *buf, size_t len, const char* address, |
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uint16_t port) |
183 |
{ |
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/* If the address-part contains a colon, it's an IPv6 IP so needs [] */
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if (strstr(address, ":")) { |
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snprintf(buf, len, "[%s]:%u", address, port);
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} else {
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snprintf(buf, len, "%s:%u", address, port);
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} |
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} |
191 |
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int tcp_socket_outgoing(const char *address, uint16_t port) |
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{ |
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char address_and_port[128]; |
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combine_addr(address_and_port, 128, address, port);
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return tcp_socket_outgoing_spec(address_and_port);
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} |
198 |
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int tcp_socket_outgoing_spec(const char *address_and_port) |
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{ |
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return inet_connect(address_and_port, true, NULL, NULL); |
202 |
} |
203 |
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int tcp_socket_incoming(const char *address, uint16_t port) |
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{ |
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char address_and_port[128]; |
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combine_addr(address_and_port, 128, address, port);
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return tcp_socket_incoming_spec(address_and_port);
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} |
210 |
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int tcp_socket_incoming_spec(const char *address_and_port) |
212 |
{ |
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char *ostr = NULL; |
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int olen = 0; |
215 |
return inet_listen(address_and_port, ostr, olen, SOCK_STREAM, 0, NULL); |
216 |
} |
217 |
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int unix_socket_incoming(const char *path) |
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{ |
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char *ostr = NULL; |
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int olen = 0; |
222 |
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return unix_listen(path, ostr, olen);
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} |
225 |
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int unix_socket_outgoing(const char *path) |
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{ |
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return unix_connect(path);
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} |
230 |
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/* Basic flow
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Server Client
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Negotiate
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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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static int nbd_send_negotiate(NBDClient *client) |
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{ |
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int csock = client->sock;
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char buf[8 + 8 + 8 + 128]; |
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int rc;
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/* Negotiate
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[ 0 .. 7] passwd ("NBDMAGIC")
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[ 8 .. 15] magic (NBD_CLIENT_MAGIC)
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[16 .. 23] size
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[24 .. 27] flags
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[28 .. 151] reserved (0)
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*/
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socket_set_block(csock); |
260 |
rc = -EINVAL; |
261 |
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TRACE("Beginning negotiation.");
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memcpy(buf, "NBDMAGIC", 8); |
264 |
cpu_to_be64w((uint64_t*)(buf + 8), NBD_CLIENT_MAGIC);
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cpu_to_be64w((uint64_t*)(buf + 16), client->exp->size);
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cpu_to_be32w((uint32_t*)(buf + 24),
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client->exp->nbdflags | NBD_FLAG_HAS_FLAGS | NBD_FLAG_SEND_TRIM | |
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NBD_FLAG_SEND_FLUSH | NBD_FLAG_SEND_FUA); |
269 |
memset(buf + 28, 0, 124); |
270 |
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if (write_sync(csock, buf, sizeof(buf)) != sizeof(buf)) { |
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LOG("write failed");
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goto fail;
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} |
275 |
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TRACE("Negotiation succeeded.");
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rc = 0;
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fail:
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279 |
socket_set_nonblock(csock); |
280 |
return rc;
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} |
282 |
|
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int nbd_receive_negotiate(int csock, const char *name, uint32_t *flags, |
284 |
off_t *size, size_t *blocksize) |
285 |
{ |
286 |
char buf[256]; |
287 |
uint64_t magic, s; |
288 |
uint16_t tmp; |
289 |
int rc;
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290 |
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TRACE("Receiving negotiation.");
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293 |
socket_set_block(csock); |
294 |
rc = -EINVAL; |
295 |
|
296 |
if (read_sync(csock, buf, 8) != 8) { |
297 |
LOG("read failed");
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goto fail;
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299 |
} |
300 |
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301 |
buf[8] = '\0'; |
302 |
if (strlen(buf) == 0) { |
303 |
LOG("server connection closed");
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304 |
goto fail;
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305 |
} |
306 |
|
307 |
TRACE("Magic is %c%c%c%c%c%c%c%c",
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308 |
qemu_isprint(buf[0]) ? buf[0] : '.', |
309 |
qemu_isprint(buf[1]) ? buf[1] : '.', |
310 |
qemu_isprint(buf[2]) ? buf[2] : '.', |
311 |
qemu_isprint(buf[3]) ? buf[3] : '.', |
312 |
qemu_isprint(buf[4]) ? buf[4] : '.', |
313 |
qemu_isprint(buf[5]) ? buf[5] : '.', |
314 |
qemu_isprint(buf[6]) ? buf[6] : '.', |
315 |
qemu_isprint(buf[7]) ? buf[7] : '.'); |
316 |
|
317 |
if (memcmp(buf, "NBDMAGIC", 8) != 0) { |
318 |
LOG("Invalid magic received");
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319 |
goto fail;
|
320 |
} |
321 |
|
322 |
if (read_sync(csock, &magic, sizeof(magic)) != sizeof(magic)) { |
323 |
LOG("read failed");
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324 |
goto fail;
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325 |
} |
326 |
magic = be64_to_cpu(magic); |
327 |
TRACE("Magic is 0x%" PRIx64, magic);
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328 |
|
329 |
if (name) {
|
330 |
uint32_t reserved = 0;
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331 |
uint32_t opt; |
332 |
uint32_t namesize; |
333 |
|
334 |
TRACE("Checking magic (opts_magic)");
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335 |
if (magic != NBD_OPTS_MAGIC) {
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336 |
LOG("Bad magic received");
|
337 |
goto fail;
|
338 |
} |
339 |
if (read_sync(csock, &tmp, sizeof(tmp)) != sizeof(tmp)) { |
340 |
LOG("flags read failed");
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341 |
goto fail;
|
342 |
} |
343 |
*flags = be16_to_cpu(tmp) << 16;
|
344 |
/* reserved for future use */
|
345 |
if (write_sync(csock, &reserved, sizeof(reserved)) != |
346 |
sizeof(reserved)) {
|
347 |
LOG("write failed (reserved)");
|
348 |
goto fail;
|
349 |
} |
350 |
/* write the export name */
|
351 |
magic = cpu_to_be64(magic); |
352 |
if (write_sync(csock, &magic, sizeof(magic)) != sizeof(magic)) { |
353 |
LOG("write failed (magic)");
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354 |
goto fail;
|
355 |
} |
356 |
opt = cpu_to_be32(NBD_OPT_EXPORT_NAME); |
357 |
if (write_sync(csock, &opt, sizeof(opt)) != sizeof(opt)) { |
358 |
LOG("write failed (opt)");
|
359 |
goto fail;
|
360 |
} |
361 |
namesize = cpu_to_be32(strlen(name)); |
362 |
if (write_sync(csock, &namesize, sizeof(namesize)) != |
363 |
sizeof(namesize)) {
|
364 |
LOG("write failed (namesize)");
|
365 |
goto fail;
|
366 |
} |
367 |
if (write_sync(csock, (char*)name, strlen(name)) != strlen(name)) { |
368 |
LOG("write failed (name)");
|
369 |
goto fail;
|
370 |
} |
371 |
} else {
|
372 |
TRACE("Checking magic (cli_magic)");
|
373 |
|
374 |
if (magic != NBD_CLIENT_MAGIC) {
|
375 |
LOG("Bad magic received");
|
376 |
goto fail;
|
377 |
} |
378 |
} |
379 |
|
380 |
if (read_sync(csock, &s, sizeof(s)) != sizeof(s)) { |
381 |
LOG("read failed");
|
382 |
goto fail;
|
383 |
} |
384 |
*size = be64_to_cpu(s); |
385 |
*blocksize = 1024;
|
386 |
TRACE("Size is %" PRIu64, *size);
|
387 |
|
388 |
if (!name) {
|
389 |
if (read_sync(csock, flags, sizeof(*flags)) != sizeof(*flags)) { |
390 |
LOG("read failed (flags)");
|
391 |
goto fail;
|
392 |
} |
393 |
*flags = be32_to_cpup(flags); |
394 |
} else {
|
395 |
if (read_sync(csock, &tmp, sizeof(tmp)) != sizeof(tmp)) { |
396 |
LOG("read failed (tmp)");
|
397 |
goto fail;
|
398 |
} |
399 |
*flags |= be32_to_cpu(tmp); |
400 |
} |
401 |
if (read_sync(csock, &buf, 124) != 124) { |
402 |
LOG("read failed (buf)");
|
403 |
goto fail;
|
404 |
} |
405 |
rc = 0;
|
406 |
|
407 |
fail:
|
408 |
socket_set_nonblock(csock); |
409 |
return rc;
|
410 |
} |
411 |
|
412 |
#ifdef __linux__
|
413 |
int nbd_init(int fd, int csock, uint32_t flags, off_t size, size_t blocksize) |
414 |
{ |
415 |
TRACE("Setting NBD socket");
|
416 |
|
417 |
if (ioctl(fd, NBD_SET_SOCK, csock) < 0) { |
418 |
int serrno = errno;
|
419 |
LOG("Failed to set NBD socket");
|
420 |
return -serrno;
|
421 |
} |
422 |
|
423 |
TRACE("Setting block size to %lu", (unsigned long)blocksize); |
424 |
|
425 |
if (ioctl(fd, NBD_SET_BLKSIZE, blocksize) < 0) { |
426 |
int serrno = errno;
|
427 |
LOG("Failed setting NBD block size");
|
428 |
return -serrno;
|
429 |
} |
430 |
|
431 |
TRACE("Setting size to %zd block(s)", (size_t)(size / blocksize));
|
432 |
|
433 |
if (ioctl(fd, NBD_SET_SIZE_BLOCKS, size / blocksize) < 0) { |
434 |
int serrno = errno;
|
435 |
LOG("Failed setting size (in blocks)");
|
436 |
return -serrno;
|
437 |
} |
438 |
|
439 |
if (flags & NBD_FLAG_READ_ONLY) {
|
440 |
int read_only = 1; |
441 |
TRACE("Setting readonly attribute");
|
442 |
|
443 |
if (ioctl(fd, BLKROSET, (unsigned long) &read_only) < 0) { |
444 |
int serrno = errno;
|
445 |
LOG("Failed setting read-only attribute");
|
446 |
return -serrno;
|
447 |
} |
448 |
} |
449 |
|
450 |
if (ioctl(fd, NBD_SET_FLAGS, flags) < 0 |
451 |
&& errno != ENOTTY) { |
452 |
int serrno = errno;
|
453 |
LOG("Failed setting flags");
|
454 |
return -serrno;
|
455 |
} |
456 |
|
457 |
TRACE("Negotiation ended");
|
458 |
|
459 |
return 0; |
460 |
} |
461 |
|
462 |
int nbd_disconnect(int fd) |
463 |
{ |
464 |
ioctl(fd, NBD_CLEAR_QUE); |
465 |
ioctl(fd, NBD_DISCONNECT); |
466 |
ioctl(fd, NBD_CLEAR_SOCK); |
467 |
return 0; |
468 |
} |
469 |
|
470 |
int nbd_client(int fd) |
471 |
{ |
472 |
int ret;
|
473 |
int serrno;
|
474 |
|
475 |
TRACE("Doing NBD loop");
|
476 |
|
477 |
ret = ioctl(fd, NBD_DO_IT); |
478 |
if (ret < 0 && errno == EPIPE) { |
479 |
/* NBD_DO_IT normally returns EPIPE when someone has disconnected
|
480 |
* the socket via NBD_DISCONNECT. We do not want to return 1 in
|
481 |
* that case.
|
482 |
*/
|
483 |
ret = 0;
|
484 |
} |
485 |
serrno = errno; |
486 |
|
487 |
TRACE("NBD loop returned %d: %s", ret, strerror(serrno));
|
488 |
|
489 |
TRACE("Clearing NBD queue");
|
490 |
ioctl(fd, NBD_CLEAR_QUE); |
491 |
|
492 |
TRACE("Clearing NBD socket");
|
493 |
ioctl(fd, NBD_CLEAR_SOCK); |
494 |
|
495 |
errno = serrno; |
496 |
return ret;
|
497 |
} |
498 |
#else
|
499 |
int nbd_init(int fd, int csock, uint32_t flags, off_t size, size_t blocksize) |
500 |
{ |
501 |
return -ENOTSUP;
|
502 |
} |
503 |
|
504 |
int nbd_disconnect(int fd) |
505 |
{ |
506 |
return -ENOTSUP;
|
507 |
} |
508 |
|
509 |
int nbd_client(int fd) |
510 |
{ |
511 |
return -ENOTSUP;
|
512 |
} |
513 |
#endif
|
514 |
|
515 |
ssize_t nbd_send_request(int csock, struct nbd_request *request) |
516 |
{ |
517 |
uint8_t buf[NBD_REQUEST_SIZE]; |
518 |
ssize_t ret; |
519 |
|
520 |
cpu_to_be32w((uint32_t*)buf, NBD_REQUEST_MAGIC); |
521 |
cpu_to_be32w((uint32_t*)(buf + 4), request->type);
|
522 |
cpu_to_be64w((uint64_t*)(buf + 8), request->handle);
|
523 |
cpu_to_be64w((uint64_t*)(buf + 16), request->from);
|
524 |
cpu_to_be32w((uint32_t*)(buf + 24), request->len);
|
525 |
|
526 |
TRACE("Sending request to client: "
|
527 |
"{ .from = %" PRIu64", .len = %u, .handle = %" PRIu64", .type=%i}", |
528 |
request->from, request->len, request->handle, request->type); |
529 |
|
530 |
ret = write_sync(csock, buf, sizeof(buf));
|
531 |
if (ret < 0) { |
532 |
return ret;
|
533 |
} |
534 |
|
535 |
if (ret != sizeof(buf)) { |
536 |
LOG("writing to socket failed");
|
537 |
return -EINVAL;
|
538 |
} |
539 |
return 0; |
540 |
} |
541 |
|
542 |
static ssize_t nbd_receive_request(int csock, struct nbd_request *request) |
543 |
{ |
544 |
uint8_t buf[NBD_REQUEST_SIZE]; |
545 |
uint32_t magic; |
546 |
ssize_t ret; |
547 |
|
548 |
ret = read_sync(csock, buf, sizeof(buf));
|
549 |
if (ret < 0) { |
550 |
return ret;
|
551 |
} |
552 |
|
553 |
if (ret != sizeof(buf)) { |
554 |
LOG("read failed");
|
555 |
return -EINVAL;
|
556 |
} |
557 |
|
558 |
/* Request
|
559 |
[ 0 .. 3] magic (NBD_REQUEST_MAGIC)
|
560 |
[ 4 .. 7] type (0 == READ, 1 == WRITE)
|
561 |
[ 8 .. 15] handle
|
562 |
[16 .. 23] from
|
563 |
[24 .. 27] len
|
564 |
*/
|
565 |
|
566 |
magic = be32_to_cpup((uint32_t*)buf); |
567 |
request->type = be32_to_cpup((uint32_t*)(buf + 4));
|
568 |
request->handle = be64_to_cpup((uint64_t*)(buf + 8));
|
569 |
request->from = be64_to_cpup((uint64_t*)(buf + 16));
|
570 |
request->len = be32_to_cpup((uint32_t*)(buf + 24));
|
571 |
|
572 |
TRACE("Got request: "
|
573 |
"{ magic = 0x%x, .type = %d, from = %" PRIu64" , len = %u }", |
574 |
magic, request->type, request->from, request->len); |
575 |
|
576 |
if (magic != NBD_REQUEST_MAGIC) {
|
577 |
LOG("invalid magic (got 0x%x)", magic);
|
578 |
return -EINVAL;
|
579 |
} |
580 |
return 0; |
581 |
} |
582 |
|
583 |
ssize_t nbd_receive_reply(int csock, struct nbd_reply *reply) |
584 |
{ |
585 |
uint8_t buf[NBD_REPLY_SIZE]; |
586 |
uint32_t magic; |
587 |
ssize_t ret; |
588 |
|
589 |
ret = read_sync(csock, buf, sizeof(buf));
|
590 |
if (ret < 0) { |
591 |
return ret;
|
592 |
} |
593 |
|
594 |
if (ret != sizeof(buf)) { |
595 |
LOG("read failed");
|
596 |
return -EINVAL;
|
597 |
} |
598 |
|
599 |
/* Reply
|
600 |
[ 0 .. 3] magic (NBD_REPLY_MAGIC)
|
601 |
[ 4 .. 7] error (0 == no error)
|
602 |
[ 7 .. 15] handle
|
603 |
*/
|
604 |
|
605 |
magic = be32_to_cpup((uint32_t*)buf); |
606 |
reply->error = be32_to_cpup((uint32_t*)(buf + 4));
|
607 |
reply->handle = be64_to_cpup((uint64_t*)(buf + 8));
|
608 |
|
609 |
TRACE("Got reply: "
|
610 |
"{ magic = 0x%x, .error = %d, handle = %" PRIu64" }", |
611 |
magic, reply->error, reply->handle); |
612 |
|
613 |
if (magic != NBD_REPLY_MAGIC) {
|
614 |
LOG("invalid magic (got 0x%x)", magic);
|
615 |
return -EINVAL;
|
616 |
} |
617 |
return 0; |
618 |
} |
619 |
|
620 |
static ssize_t nbd_send_reply(int csock, struct nbd_reply *reply) |
621 |
{ |
622 |
uint8_t buf[NBD_REPLY_SIZE]; |
623 |
ssize_t ret; |
624 |
|
625 |
/* Reply
|
626 |
[ 0 .. 3] magic (NBD_REPLY_MAGIC)
|
627 |
[ 4 .. 7] error (0 == no error)
|
628 |
[ 7 .. 15] handle
|
629 |
*/
|
630 |
cpu_to_be32w((uint32_t*)buf, NBD_REPLY_MAGIC); |
631 |
cpu_to_be32w((uint32_t*)(buf + 4), reply->error);
|
632 |
cpu_to_be64w((uint64_t*)(buf + 8), reply->handle);
|
633 |
|
634 |
TRACE("Sending response to client");
|
635 |
|
636 |
ret = write_sync(csock, buf, sizeof(buf));
|
637 |
if (ret < 0) { |
638 |
return ret;
|
639 |
} |
640 |
|
641 |
if (ret != sizeof(buf)) { |
642 |
LOG("writing to socket failed");
|
643 |
return -EINVAL;
|
644 |
} |
645 |
return 0; |
646 |
} |
647 |
|
648 |
#define MAX_NBD_REQUESTS 16 |
649 |
|
650 |
static void nbd_client_get(NBDClient *client) |
651 |
{ |
652 |
client->refcount++; |
653 |
} |
654 |
|
655 |
static void nbd_client_put(NBDClient *client) |
656 |
{ |
657 |
if (--client->refcount == 0) { |
658 |
g_free(client); |
659 |
} |
660 |
} |
661 |
|
662 |
static void nbd_client_close(NBDClient *client) |
663 |
{ |
664 |
qemu_set_fd_handler2(client->sock, NULL, NULL, NULL, NULL); |
665 |
close(client->sock); |
666 |
client->sock = -1;
|
667 |
if (client->close) {
|
668 |
client->close(client); |
669 |
} |
670 |
nbd_client_put(client); |
671 |
} |
672 |
|
673 |
static NBDRequest *nbd_request_get(NBDClient *client)
|
674 |
{ |
675 |
NBDRequest *req; |
676 |
NBDExport *exp = client->exp; |
677 |
|
678 |
assert(client->nb_requests <= MAX_NBD_REQUESTS - 1);
|
679 |
client->nb_requests++; |
680 |
|
681 |
if (QSIMPLEQ_EMPTY(&exp->requests)) {
|
682 |
req = g_malloc0(sizeof(NBDRequest));
|
683 |
req->data = qemu_blockalign(exp->bs, NBD_BUFFER_SIZE); |
684 |
} else {
|
685 |
req = QSIMPLEQ_FIRST(&exp->requests); |
686 |
QSIMPLEQ_REMOVE_HEAD(&exp->requests, entry); |
687 |
} |
688 |
nbd_client_get(client); |
689 |
req->client = client; |
690 |
return req;
|
691 |
} |
692 |
|
693 |
static void nbd_request_put(NBDRequest *req) |
694 |
{ |
695 |
NBDClient *client = req->client; |
696 |
QSIMPLEQ_INSERT_HEAD(&client->exp->requests, req, entry); |
697 |
if (client->nb_requests-- == MAX_NBD_REQUESTS) {
|
698 |
qemu_notify_event(); |
699 |
} |
700 |
nbd_client_put(client); |
701 |
} |
702 |
|
703 |
NBDExport *nbd_export_new(BlockDriverState *bs, off_t dev_offset, |
704 |
off_t size, uint32_t nbdflags) |
705 |
{ |
706 |
NBDExport *exp = g_malloc0(sizeof(NBDExport));
|
707 |
QSIMPLEQ_INIT(&exp->requests); |
708 |
exp->bs = bs; |
709 |
exp->dev_offset = dev_offset; |
710 |
exp->nbdflags = nbdflags; |
711 |
exp->size = size == -1 ? bdrv_getlength(bs) : size;
|
712 |
return exp;
|
713 |
} |
714 |
|
715 |
void nbd_export_close(NBDExport *exp)
|
716 |
{ |
717 |
while (!QSIMPLEQ_EMPTY(&exp->requests)) {
|
718 |
NBDRequest *first = QSIMPLEQ_FIRST(&exp->requests); |
719 |
QSIMPLEQ_REMOVE_HEAD(&exp->requests, entry); |
720 |
qemu_vfree(first->data); |
721 |
g_free(first); |
722 |
} |
723 |
|
724 |
g_free(exp); |
725 |
} |
726 |
|
727 |
static int nbd_can_read(void *opaque); |
728 |
static void nbd_read(void *opaque); |
729 |
static void nbd_restart_write(void *opaque); |
730 |
|
731 |
static ssize_t nbd_co_send_reply(NBDRequest *req, struct nbd_reply *reply, |
732 |
int len)
|
733 |
{ |
734 |
NBDClient *client = req->client; |
735 |
int csock = client->sock;
|
736 |
ssize_t rc, ret; |
737 |
|
738 |
qemu_co_mutex_lock(&client->send_lock); |
739 |
qemu_set_fd_handler2(csock, nbd_can_read, nbd_read, |
740 |
nbd_restart_write, client); |
741 |
client->send_coroutine = qemu_coroutine_self(); |
742 |
|
743 |
if (!len) {
|
744 |
rc = nbd_send_reply(csock, reply); |
745 |
} else {
|
746 |
socket_set_cork(csock, 1);
|
747 |
rc = nbd_send_reply(csock, reply); |
748 |
if (rc >= 0) { |
749 |
ret = qemu_co_send(csock, req->data, len); |
750 |
if (ret != len) {
|
751 |
rc = -EIO; |
752 |
} |
753 |
} |
754 |
socket_set_cork(csock, 0);
|
755 |
} |
756 |
|
757 |
client->send_coroutine = NULL;
|
758 |
qemu_set_fd_handler2(csock, nbd_can_read, nbd_read, NULL, client);
|
759 |
qemu_co_mutex_unlock(&client->send_lock); |
760 |
return rc;
|
761 |
} |
762 |
|
763 |
static ssize_t nbd_co_receive_request(NBDRequest *req, struct nbd_request *request) |
764 |
{ |
765 |
NBDClient *client = req->client; |
766 |
int csock = client->sock;
|
767 |
ssize_t rc; |
768 |
|
769 |
client->recv_coroutine = qemu_coroutine_self(); |
770 |
rc = nbd_receive_request(csock, request); |
771 |
if (rc < 0) { |
772 |
if (rc != -EAGAIN) {
|
773 |
rc = -EIO; |
774 |
} |
775 |
goto out;
|
776 |
} |
777 |
|
778 |
if (request->len > NBD_BUFFER_SIZE) {
|
779 |
LOG("len (%u) is larger than max len (%u)",
|
780 |
request->len, NBD_BUFFER_SIZE); |
781 |
rc = -EINVAL; |
782 |
goto out;
|
783 |
} |
784 |
|
785 |
if ((request->from + request->len) < request->from) {
|
786 |
LOG("integer overflow detected! "
|
787 |
"you're probably being attacked");
|
788 |
rc = -EINVAL; |
789 |
goto out;
|
790 |
} |
791 |
|
792 |
TRACE("Decoding type");
|
793 |
|
794 |
if ((request->type & NBD_CMD_MASK_COMMAND) == NBD_CMD_WRITE) {
|
795 |
TRACE("Reading %u byte(s)", request->len);
|
796 |
|
797 |
if (qemu_co_recv(csock, req->data, request->len) != request->len) {
|
798 |
LOG("reading from socket failed");
|
799 |
rc = -EIO; |
800 |
goto out;
|
801 |
} |
802 |
} |
803 |
rc = 0;
|
804 |
|
805 |
out:
|
806 |
client->recv_coroutine = NULL;
|
807 |
return rc;
|
808 |
} |
809 |
|
810 |
static void nbd_trip(void *opaque) |
811 |
{ |
812 |
NBDClient *client = opaque; |
813 |
NBDRequest *req = nbd_request_get(client); |
814 |
NBDExport *exp = client->exp; |
815 |
struct nbd_request request;
|
816 |
struct nbd_reply reply;
|
817 |
ssize_t ret; |
818 |
|
819 |
TRACE("Reading request.");
|
820 |
|
821 |
ret = nbd_co_receive_request(req, &request); |
822 |
if (ret == -EAGAIN) {
|
823 |
goto done;
|
824 |
} |
825 |
if (ret == -EIO) {
|
826 |
goto out;
|
827 |
} |
828 |
|
829 |
reply.handle = request.handle; |
830 |
reply.error = 0;
|
831 |
|
832 |
if (ret < 0) { |
833 |
reply.error = -ret; |
834 |
goto error_reply;
|
835 |
} |
836 |
|
837 |
if ((request.from + request.len) > exp->size) {
|
838 |
LOG("From: %" PRIu64 ", Len: %u, Size: %" PRIu64 |
839 |
", Offset: %" PRIu64 "\n", |
840 |
request.from, request.len, |
841 |
(uint64_t)exp->size, (uint64_t)exp->dev_offset); |
842 |
LOG("requested operation past EOF--bad client?");
|
843 |
goto invalid_request;
|
844 |
} |
845 |
|
846 |
switch (request.type & NBD_CMD_MASK_COMMAND) {
|
847 |
case NBD_CMD_READ:
|
848 |
TRACE("Request type is READ");
|
849 |
|
850 |
if (request.type & NBD_CMD_FLAG_FUA) {
|
851 |
ret = bdrv_co_flush(exp->bs); |
852 |
if (ret < 0) { |
853 |
LOG("flush failed");
|
854 |
reply.error = -ret; |
855 |
goto error_reply;
|
856 |
} |
857 |
} |
858 |
|
859 |
ret = bdrv_read(exp->bs, (request.from + exp->dev_offset) / 512,
|
860 |
req->data, request.len / 512);
|
861 |
if (ret < 0) { |
862 |
LOG("reading from file failed");
|
863 |
reply.error = -ret; |
864 |
goto error_reply;
|
865 |
} |
866 |
|
867 |
TRACE("Read %u byte(s)", request.len);
|
868 |
if (nbd_co_send_reply(req, &reply, request.len) < 0) |
869 |
goto out;
|
870 |
break;
|
871 |
case NBD_CMD_WRITE:
|
872 |
TRACE("Request type is WRITE");
|
873 |
|
874 |
if (exp->nbdflags & NBD_FLAG_READ_ONLY) {
|
875 |
TRACE("Server is read-only, return error");
|
876 |
reply.error = EROFS; |
877 |
goto error_reply;
|
878 |
} |
879 |
|
880 |
TRACE("Writing to device");
|
881 |
|
882 |
ret = bdrv_write(exp->bs, (request.from + exp->dev_offset) / 512,
|
883 |
req->data, request.len / 512);
|
884 |
if (ret < 0) { |
885 |
LOG("writing to file failed");
|
886 |
reply.error = -ret; |
887 |
goto error_reply;
|
888 |
} |
889 |
|
890 |
if (request.type & NBD_CMD_FLAG_FUA) {
|
891 |
ret = bdrv_co_flush(exp->bs); |
892 |
if (ret < 0) { |
893 |
LOG("flush failed");
|
894 |
reply.error = -ret; |
895 |
goto error_reply;
|
896 |
} |
897 |
} |
898 |
|
899 |
if (nbd_co_send_reply(req, &reply, 0) < 0) { |
900 |
goto out;
|
901 |
} |
902 |
break;
|
903 |
case NBD_CMD_DISC:
|
904 |
TRACE("Request type is DISCONNECT");
|
905 |
errno = 0;
|
906 |
goto out;
|
907 |
case NBD_CMD_FLUSH:
|
908 |
TRACE("Request type is FLUSH");
|
909 |
|
910 |
ret = bdrv_co_flush(exp->bs); |
911 |
if (ret < 0) { |
912 |
LOG("flush failed");
|
913 |
reply.error = -ret; |
914 |
} |
915 |
if (nbd_co_send_reply(req, &reply, 0) < 0) { |
916 |
goto out;
|
917 |
} |
918 |
break;
|
919 |
case NBD_CMD_TRIM:
|
920 |
TRACE("Request type is TRIM");
|
921 |
ret = bdrv_co_discard(exp->bs, (request.from + exp->dev_offset) / 512,
|
922 |
request.len / 512);
|
923 |
if (ret < 0) { |
924 |
LOG("discard failed");
|
925 |
reply.error = -ret; |
926 |
} |
927 |
if (nbd_co_send_reply(req, &reply, 0) < 0) { |
928 |
goto out;
|
929 |
} |
930 |
break;
|
931 |
default:
|
932 |
LOG("invalid request type (%u) received", request.type);
|
933 |
invalid_request:
|
934 |
reply.error = -EINVAL; |
935 |
error_reply:
|
936 |
if (nbd_co_send_reply(req, &reply, 0) < 0) { |
937 |
goto out;
|
938 |
} |
939 |
break;
|
940 |
} |
941 |
|
942 |
TRACE("Request/Reply complete");
|
943 |
|
944 |
done:
|
945 |
nbd_request_put(req); |
946 |
return;
|
947 |
|
948 |
out:
|
949 |
nbd_request_put(req); |
950 |
nbd_client_close(client); |
951 |
} |
952 |
|
953 |
static int nbd_can_read(void *opaque) |
954 |
{ |
955 |
NBDClient *client = opaque; |
956 |
|
957 |
return client->recv_coroutine || client->nb_requests < MAX_NBD_REQUESTS;
|
958 |
} |
959 |
|
960 |
static void nbd_read(void *opaque) |
961 |
{ |
962 |
NBDClient *client = opaque; |
963 |
|
964 |
if (client->recv_coroutine) {
|
965 |
qemu_coroutine_enter(client->recv_coroutine, NULL);
|
966 |
} else {
|
967 |
qemu_coroutine_enter(qemu_coroutine_create(nbd_trip), client); |
968 |
} |
969 |
} |
970 |
|
971 |
static void nbd_restart_write(void *opaque) |
972 |
{ |
973 |
NBDClient *client = opaque; |
974 |
|
975 |
qemu_coroutine_enter(client->send_coroutine, NULL);
|
976 |
} |
977 |
|
978 |
NBDClient *nbd_client_new(NBDExport *exp, int csock,
|
979 |
void (*close)(NBDClient *))
|
980 |
{ |
981 |
NBDClient *client; |
982 |
client = g_malloc0(sizeof(NBDClient));
|
983 |
client->refcount = 1;
|
984 |
client->exp = exp; |
985 |
client->sock = csock; |
986 |
if (nbd_send_negotiate(client) < 0) { |
987 |
g_free(client); |
988 |
return NULL; |
989 |
} |
990 |
client->close = close; |
991 |
qemu_co_mutex_init(&client->send_lock); |
992 |
qemu_set_fd_handler2(csock, nbd_can_read, nbd_read, NULL, client);
|
993 |
return client;
|
994 |
} |