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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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|
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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) |
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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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#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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int refcount;
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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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}; |
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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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Coroutine *recv_coroutine; |
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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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bool closing;
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}; |
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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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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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} |
130 |
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while (offset < size) {
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ssize_t len; |
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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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} |
139 |
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if (len < 0) { |
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err = socket_error(); |
142 |
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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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} |
147 |
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/* unrecoverable error */
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return -err;
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} |
151 |
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/* eof */
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if (len == 0) { |
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break;
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} |
156 |
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offset += len; |
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} |
159 |
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return offset;
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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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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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static void combine_addr(char *buf, size_t len, const char* address, |
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uint16_t port) |
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{ |
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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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} |
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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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} |
200 |
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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); |
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} |
205 |
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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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} |
212 |
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int tcp_socket_incoming_spec(const char *address_and_port) |
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{ |
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char *ostr = NULL; |
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int olen = 0; |
217 |
return inet_listen(address_and_port, ostr, olen, SOCK_STREAM, 0, NULL); |
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} |
219 |
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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; |
224 |
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return unix_listen(path, ostr, olen);
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} |
227 |
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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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} |
232 |
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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); |
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rc = -EINVAL; |
263 |
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TRACE("Beginning negotiation.");
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memcpy(buf, "NBDMAGIC", 8); |
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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); |
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memset(buf + 28, 0, 124); |
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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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} |
277 |
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TRACE("Negotiation succeeded.");
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rc = 0;
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fail:
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socket_set_nonblock(csock); |
282 |
return rc;
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} |
284 |
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int nbd_receive_negotiate(int csock, const char *name, uint32_t *flags, |
286 |
off_t *size, size_t *blocksize) |
287 |
{ |
288 |
char buf[256]; |
289 |
uint64_t magic, s; |
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uint16_t tmp; |
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int rc;
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TRACE("Receiving negotiation.");
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socket_set_block(csock); |
296 |
rc = -EINVAL; |
297 |
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298 |
if (read_sync(csock, buf, 8) != 8) { |
299 |
LOG("read failed");
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goto fail;
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} |
302 |
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303 |
buf[8] = '\0'; |
304 |
if (strlen(buf) == 0) { |
305 |
LOG("server connection closed");
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306 |
goto fail;
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307 |
} |
308 |
|
309 |
TRACE("Magic is %c%c%c%c%c%c%c%c",
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310 |
qemu_isprint(buf[0]) ? buf[0] : '.', |
311 |
qemu_isprint(buf[1]) ? buf[1] : '.', |
312 |
qemu_isprint(buf[2]) ? buf[2] : '.', |
313 |
qemu_isprint(buf[3]) ? buf[3] : '.', |
314 |
qemu_isprint(buf[4]) ? buf[4] : '.', |
315 |
qemu_isprint(buf[5]) ? buf[5] : '.', |
316 |
qemu_isprint(buf[6]) ? buf[6] : '.', |
317 |
qemu_isprint(buf[7]) ? buf[7] : '.'); |
318 |
|
319 |
if (memcmp(buf, "NBDMAGIC", 8) != 0) { |
320 |
LOG("Invalid magic received");
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321 |
goto fail;
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322 |
} |
323 |
|
324 |
if (read_sync(csock, &magic, sizeof(magic)) != sizeof(magic)) { |
325 |
LOG("read failed");
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326 |
goto fail;
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327 |
} |
328 |
magic = be64_to_cpu(magic); |
329 |
TRACE("Magic is 0x%" PRIx64, magic);
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330 |
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331 |
if (name) {
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332 |
uint32_t reserved = 0;
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333 |
uint32_t opt; |
334 |
uint32_t namesize; |
335 |
|
336 |
TRACE("Checking magic (opts_magic)");
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337 |
if (magic != NBD_OPTS_MAGIC) {
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338 |
LOG("Bad magic received");
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339 |
goto fail;
|
340 |
} |
341 |
if (read_sync(csock, &tmp, sizeof(tmp)) != sizeof(tmp)) { |
342 |
LOG("flags read failed");
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343 |
goto fail;
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344 |
} |
345 |
*flags = be16_to_cpu(tmp) << 16;
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346 |
/* reserved for future use */
|
347 |
if (write_sync(csock, &reserved, sizeof(reserved)) != |
348 |
sizeof(reserved)) {
|
349 |
LOG("write failed (reserved)");
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350 |
goto fail;
|
351 |
} |
352 |
/* write the export name */
|
353 |
magic = cpu_to_be64(magic); |
354 |
if (write_sync(csock, &magic, sizeof(magic)) != sizeof(magic)) { |
355 |
LOG("write failed (magic)");
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356 |
goto fail;
|
357 |
} |
358 |
opt = cpu_to_be32(NBD_OPT_EXPORT_NAME); |
359 |
if (write_sync(csock, &opt, sizeof(opt)) != sizeof(opt)) { |
360 |
LOG("write failed (opt)");
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361 |
goto fail;
|
362 |
} |
363 |
namesize = cpu_to_be32(strlen(name)); |
364 |
if (write_sync(csock, &namesize, sizeof(namesize)) != |
365 |
sizeof(namesize)) {
|
366 |
LOG("write failed (namesize)");
|
367 |
goto fail;
|
368 |
} |
369 |
if (write_sync(csock, (char*)name, strlen(name)) != strlen(name)) { |
370 |
LOG("write failed (name)");
|
371 |
goto fail;
|
372 |
} |
373 |
} else {
|
374 |
TRACE("Checking magic (cli_magic)");
|
375 |
|
376 |
if (magic != NBD_CLIENT_MAGIC) {
|
377 |
LOG("Bad magic received");
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378 |
goto fail;
|
379 |
} |
380 |
} |
381 |
|
382 |
if (read_sync(csock, &s, sizeof(s)) != sizeof(s)) { |
383 |
LOG("read failed");
|
384 |
goto fail;
|
385 |
} |
386 |
*size = be64_to_cpu(s); |
387 |
*blocksize = 1024;
|
388 |
TRACE("Size is %" PRIu64, *size);
|
389 |
|
390 |
if (!name) {
|
391 |
if (read_sync(csock, flags, sizeof(*flags)) != sizeof(*flags)) { |
392 |
LOG("read failed (flags)");
|
393 |
goto fail;
|
394 |
} |
395 |
*flags = be32_to_cpup(flags); |
396 |
} else {
|
397 |
if (read_sync(csock, &tmp, sizeof(tmp)) != sizeof(tmp)) { |
398 |
LOG("read failed (tmp)");
|
399 |
goto fail;
|
400 |
} |
401 |
*flags |= be32_to_cpu(tmp); |
402 |
} |
403 |
if (read_sync(csock, &buf, 124) != 124) { |
404 |
LOG("read failed (buf)");
|
405 |
goto fail;
|
406 |
} |
407 |
rc = 0;
|
408 |
|
409 |
fail:
|
410 |
socket_set_nonblock(csock); |
411 |
return rc;
|
412 |
} |
413 |
|
414 |
#ifdef __linux__
|
415 |
int nbd_init(int fd, int csock, uint32_t flags, off_t size, size_t blocksize) |
416 |
{ |
417 |
TRACE("Setting NBD socket");
|
418 |
|
419 |
if (ioctl(fd, NBD_SET_SOCK, csock) < 0) { |
420 |
int serrno = errno;
|
421 |
LOG("Failed to set NBD socket");
|
422 |
return -serrno;
|
423 |
} |
424 |
|
425 |
TRACE("Setting block size to %lu", (unsigned long)blocksize); |
426 |
|
427 |
if (ioctl(fd, NBD_SET_BLKSIZE, blocksize) < 0) { |
428 |
int serrno = errno;
|
429 |
LOG("Failed setting NBD block size");
|
430 |
return -serrno;
|
431 |
} |
432 |
|
433 |
TRACE("Setting size to %zd block(s)", (size_t)(size / blocksize));
|
434 |
|
435 |
if (ioctl(fd, NBD_SET_SIZE_BLOCKS, size / blocksize) < 0) { |
436 |
int serrno = errno;
|
437 |
LOG("Failed setting size (in blocks)");
|
438 |
return -serrno;
|
439 |
} |
440 |
|
441 |
if (flags & NBD_FLAG_READ_ONLY) {
|
442 |
int read_only = 1; |
443 |
TRACE("Setting readonly attribute");
|
444 |
|
445 |
if (ioctl(fd, BLKROSET, (unsigned long) &read_only) < 0) { |
446 |
int serrno = errno;
|
447 |
LOG("Failed setting read-only attribute");
|
448 |
return -serrno;
|
449 |
} |
450 |
} |
451 |
|
452 |
if (ioctl(fd, NBD_SET_FLAGS, flags) < 0 |
453 |
&& errno != ENOTTY) { |
454 |
int serrno = errno;
|
455 |
LOG("Failed setting flags");
|
456 |
return -serrno;
|
457 |
} |
458 |
|
459 |
TRACE("Negotiation ended");
|
460 |
|
461 |
return 0; |
462 |
} |
463 |
|
464 |
int nbd_disconnect(int fd) |
465 |
{ |
466 |
ioctl(fd, NBD_CLEAR_QUE); |
467 |
ioctl(fd, NBD_DISCONNECT); |
468 |
ioctl(fd, NBD_CLEAR_SOCK); |
469 |
return 0; |
470 |
} |
471 |
|
472 |
int nbd_client(int fd) |
473 |
{ |
474 |
int ret;
|
475 |
int serrno;
|
476 |
|
477 |
TRACE("Doing NBD loop");
|
478 |
|
479 |
ret = ioctl(fd, NBD_DO_IT); |
480 |
if (ret < 0 && errno == EPIPE) { |
481 |
/* NBD_DO_IT normally returns EPIPE when someone has disconnected
|
482 |
* the socket via NBD_DISCONNECT. We do not want to return 1 in
|
483 |
* that case.
|
484 |
*/
|
485 |
ret = 0;
|
486 |
} |
487 |
serrno = errno; |
488 |
|
489 |
TRACE("NBD loop returned %d: %s", ret, strerror(serrno));
|
490 |
|
491 |
TRACE("Clearing NBD queue");
|
492 |
ioctl(fd, NBD_CLEAR_QUE); |
493 |
|
494 |
TRACE("Clearing NBD socket");
|
495 |
ioctl(fd, NBD_CLEAR_SOCK); |
496 |
|
497 |
errno = serrno; |
498 |
return ret;
|
499 |
} |
500 |
#else
|
501 |
int nbd_init(int fd, int csock, uint32_t flags, off_t size, size_t blocksize) |
502 |
{ |
503 |
return -ENOTSUP;
|
504 |
} |
505 |
|
506 |
int nbd_disconnect(int fd) |
507 |
{ |
508 |
return -ENOTSUP;
|
509 |
} |
510 |
|
511 |
int nbd_client(int fd) |
512 |
{ |
513 |
return -ENOTSUP;
|
514 |
} |
515 |
#endif
|
516 |
|
517 |
ssize_t nbd_send_request(int csock, struct nbd_request *request) |
518 |
{ |
519 |
uint8_t buf[NBD_REQUEST_SIZE]; |
520 |
ssize_t ret; |
521 |
|
522 |
cpu_to_be32w((uint32_t*)buf, NBD_REQUEST_MAGIC); |
523 |
cpu_to_be32w((uint32_t*)(buf + 4), request->type);
|
524 |
cpu_to_be64w((uint64_t*)(buf + 8), request->handle);
|
525 |
cpu_to_be64w((uint64_t*)(buf + 16), request->from);
|
526 |
cpu_to_be32w((uint32_t*)(buf + 24), request->len);
|
527 |
|
528 |
TRACE("Sending request to client: "
|
529 |
"{ .from = %" PRIu64", .len = %u, .handle = %" PRIu64", .type=%i}", |
530 |
request->from, request->len, request->handle, request->type); |
531 |
|
532 |
ret = write_sync(csock, buf, sizeof(buf));
|
533 |
if (ret < 0) { |
534 |
return ret;
|
535 |
} |
536 |
|
537 |
if (ret != sizeof(buf)) { |
538 |
LOG("writing to socket failed");
|
539 |
return -EINVAL;
|
540 |
} |
541 |
return 0; |
542 |
} |
543 |
|
544 |
static ssize_t nbd_receive_request(int csock, struct nbd_request *request) |
545 |
{ |
546 |
uint8_t buf[NBD_REQUEST_SIZE]; |
547 |
uint32_t magic; |
548 |
ssize_t ret; |
549 |
|
550 |
ret = read_sync(csock, buf, sizeof(buf));
|
551 |
if (ret < 0) { |
552 |
return ret;
|
553 |
} |
554 |
|
555 |
if (ret != sizeof(buf)) { |
556 |
LOG("read failed");
|
557 |
return -EINVAL;
|
558 |
} |
559 |
|
560 |
/* Request
|
561 |
[ 0 .. 3] magic (NBD_REQUEST_MAGIC)
|
562 |
[ 4 .. 7] type (0 == READ, 1 == WRITE)
|
563 |
[ 8 .. 15] handle
|
564 |
[16 .. 23] from
|
565 |
[24 .. 27] len
|
566 |
*/
|
567 |
|
568 |
magic = be32_to_cpup((uint32_t*)buf); |
569 |
request->type = be32_to_cpup((uint32_t*)(buf + 4));
|
570 |
request->handle = be64_to_cpup((uint64_t*)(buf + 8));
|
571 |
request->from = be64_to_cpup((uint64_t*)(buf + 16));
|
572 |
request->len = be32_to_cpup((uint32_t*)(buf + 24));
|
573 |
|
574 |
TRACE("Got request: "
|
575 |
"{ magic = 0x%x, .type = %d, from = %" PRIu64" , len = %u }", |
576 |
magic, request->type, request->from, request->len); |
577 |
|
578 |
if (magic != NBD_REQUEST_MAGIC) {
|
579 |
LOG("invalid magic (got 0x%x)", magic);
|
580 |
return -EINVAL;
|
581 |
} |
582 |
return 0; |
583 |
} |
584 |
|
585 |
ssize_t nbd_receive_reply(int csock, struct nbd_reply *reply) |
586 |
{ |
587 |
uint8_t buf[NBD_REPLY_SIZE]; |
588 |
uint32_t magic; |
589 |
ssize_t ret; |
590 |
|
591 |
ret = read_sync(csock, buf, sizeof(buf));
|
592 |
if (ret < 0) { |
593 |
return ret;
|
594 |
} |
595 |
|
596 |
if (ret != sizeof(buf)) { |
597 |
LOG("read failed");
|
598 |
return -EINVAL;
|
599 |
} |
600 |
|
601 |
/* Reply
|
602 |
[ 0 .. 3] magic (NBD_REPLY_MAGIC)
|
603 |
[ 4 .. 7] error (0 == no error)
|
604 |
[ 7 .. 15] handle
|
605 |
*/
|
606 |
|
607 |
magic = be32_to_cpup((uint32_t*)buf); |
608 |
reply->error = be32_to_cpup((uint32_t*)(buf + 4));
|
609 |
reply->handle = be64_to_cpup((uint64_t*)(buf + 8));
|
610 |
|
611 |
TRACE("Got reply: "
|
612 |
"{ magic = 0x%x, .error = %d, handle = %" PRIu64" }", |
613 |
magic, reply->error, reply->handle); |
614 |
|
615 |
if (magic != NBD_REPLY_MAGIC) {
|
616 |
LOG("invalid magic (got 0x%x)", magic);
|
617 |
return -EINVAL;
|
618 |
} |
619 |
return 0; |
620 |
} |
621 |
|
622 |
static ssize_t nbd_send_reply(int csock, struct nbd_reply *reply) |
623 |
{ |
624 |
uint8_t buf[NBD_REPLY_SIZE]; |
625 |
ssize_t ret; |
626 |
|
627 |
/* Reply
|
628 |
[ 0 .. 3] magic (NBD_REPLY_MAGIC)
|
629 |
[ 4 .. 7] error (0 == no error)
|
630 |
[ 7 .. 15] handle
|
631 |
*/
|
632 |
cpu_to_be32w((uint32_t*)buf, NBD_REPLY_MAGIC); |
633 |
cpu_to_be32w((uint32_t*)(buf + 4), reply->error);
|
634 |
cpu_to_be64w((uint64_t*)(buf + 8), reply->handle);
|
635 |
|
636 |
TRACE("Sending response to client");
|
637 |
|
638 |
ret = write_sync(csock, buf, sizeof(buf));
|
639 |
if (ret < 0) { |
640 |
return ret;
|
641 |
} |
642 |
|
643 |
if (ret != sizeof(buf)) { |
644 |
LOG("writing to socket failed");
|
645 |
return -EINVAL;
|
646 |
} |
647 |
return 0; |
648 |
} |
649 |
|
650 |
#define MAX_NBD_REQUESTS 16 |
651 |
|
652 |
void nbd_client_get(NBDClient *client)
|
653 |
{ |
654 |
client->refcount++; |
655 |
} |
656 |
|
657 |
void nbd_client_put(NBDClient *client)
|
658 |
{ |
659 |
if (--client->refcount == 0) { |
660 |
/* The last reference should be dropped by client->close,
|
661 |
* which is called by nbd_client_close.
|
662 |
*/
|
663 |
assert(client->closing); |
664 |
|
665 |
qemu_set_fd_handler2(client->sock, NULL, NULL, NULL, NULL); |
666 |
close(client->sock); |
667 |
client->sock = -1;
|
668 |
nbd_export_put(client->exp); |
669 |
g_free(client); |
670 |
} |
671 |
} |
672 |
|
673 |
void nbd_client_close(NBDClient *client)
|
674 |
{ |
675 |
if (client->closing) {
|
676 |
return;
|
677 |
} |
678 |
|
679 |
client->closing = true;
|
680 |
|
681 |
/* Force requests to finish. They will drop their own references,
|
682 |
* then we'll close the socket and free the NBDClient.
|
683 |
*/
|
684 |
shutdown(client->sock, 2);
|
685 |
|
686 |
/* Also tell the client, so that they release their reference. */
|
687 |
if (client->close) {
|
688 |
client->close(client); |
689 |
} |
690 |
} |
691 |
|
692 |
static NBDRequest *nbd_request_get(NBDClient *client)
|
693 |
{ |
694 |
NBDRequest *req; |
695 |
NBDExport *exp = client->exp; |
696 |
|
697 |
assert(client->nb_requests <= MAX_NBD_REQUESTS - 1);
|
698 |
client->nb_requests++; |
699 |
|
700 |
if (QSIMPLEQ_EMPTY(&exp->requests)) {
|
701 |
req = g_malloc0(sizeof(NBDRequest));
|
702 |
req->data = qemu_blockalign(exp->bs, NBD_BUFFER_SIZE); |
703 |
} else {
|
704 |
req = QSIMPLEQ_FIRST(&exp->requests); |
705 |
QSIMPLEQ_REMOVE_HEAD(&exp->requests, entry); |
706 |
} |
707 |
nbd_client_get(client); |
708 |
req->client = client; |
709 |
return req;
|
710 |
} |
711 |
|
712 |
static void nbd_request_put(NBDRequest *req) |
713 |
{ |
714 |
NBDClient *client = req->client; |
715 |
QSIMPLEQ_INSERT_HEAD(&client->exp->requests, req, entry); |
716 |
if (client->nb_requests-- == MAX_NBD_REQUESTS) {
|
717 |
qemu_notify_event(); |
718 |
} |
719 |
nbd_client_put(client); |
720 |
} |
721 |
|
722 |
NBDExport *nbd_export_new(BlockDriverState *bs, off_t dev_offset, |
723 |
off_t size, uint32_t nbdflags) |
724 |
{ |
725 |
NBDExport *exp = g_malloc0(sizeof(NBDExport));
|
726 |
QSIMPLEQ_INIT(&exp->requests); |
727 |
exp->refcount = 1;
|
728 |
exp->bs = bs; |
729 |
exp->dev_offset = dev_offset; |
730 |
exp->nbdflags = nbdflags; |
731 |
exp->size = size == -1 ? bdrv_getlength(bs) : size;
|
732 |
return exp;
|
733 |
} |
734 |
|
735 |
void nbd_export_close(NBDExport *exp)
|
736 |
{ |
737 |
assert(exp->refcount == 1);
|
738 |
|
739 |
/* stub */
|
740 |
} |
741 |
|
742 |
void nbd_export_get(NBDExport *exp)
|
743 |
{ |
744 |
assert(exp->refcount > 0);
|
745 |
exp->refcount++; |
746 |
} |
747 |
|
748 |
void nbd_export_put(NBDExport *exp)
|
749 |
{ |
750 |
assert(exp->refcount > 0);
|
751 |
if (exp->refcount == 1) { |
752 |
nbd_export_close(exp); |
753 |
} |
754 |
|
755 |
if (--exp->refcount == 0) { |
756 |
while (!QSIMPLEQ_EMPTY(&exp->requests)) {
|
757 |
NBDRequest *first = QSIMPLEQ_FIRST(&exp->requests); |
758 |
QSIMPLEQ_REMOVE_HEAD(&exp->requests, entry); |
759 |
qemu_vfree(first->data); |
760 |
g_free(first); |
761 |
} |
762 |
|
763 |
g_free(exp); |
764 |
} |
765 |
} |
766 |
|
767 |
static int nbd_can_read(void *opaque); |
768 |
static void nbd_read(void *opaque); |
769 |
static void nbd_restart_write(void *opaque); |
770 |
|
771 |
static ssize_t nbd_co_send_reply(NBDRequest *req, struct nbd_reply *reply, |
772 |
int len)
|
773 |
{ |
774 |
NBDClient *client = req->client; |
775 |
int csock = client->sock;
|
776 |
ssize_t rc, ret; |
777 |
|
778 |
qemu_co_mutex_lock(&client->send_lock); |
779 |
qemu_set_fd_handler2(csock, nbd_can_read, nbd_read, |
780 |
nbd_restart_write, client); |
781 |
client->send_coroutine = qemu_coroutine_self(); |
782 |
|
783 |
if (!len) {
|
784 |
rc = nbd_send_reply(csock, reply); |
785 |
} else {
|
786 |
socket_set_cork(csock, 1);
|
787 |
rc = nbd_send_reply(csock, reply); |
788 |
if (rc >= 0) { |
789 |
ret = qemu_co_send(csock, req->data, len); |
790 |
if (ret != len) {
|
791 |
rc = -EIO; |
792 |
} |
793 |
} |
794 |
socket_set_cork(csock, 0);
|
795 |
} |
796 |
|
797 |
client->send_coroutine = NULL;
|
798 |
qemu_set_fd_handler2(csock, nbd_can_read, nbd_read, NULL, client);
|
799 |
qemu_co_mutex_unlock(&client->send_lock); |
800 |
return rc;
|
801 |
} |
802 |
|
803 |
static ssize_t nbd_co_receive_request(NBDRequest *req, struct nbd_request *request) |
804 |
{ |
805 |
NBDClient *client = req->client; |
806 |
int csock = client->sock;
|
807 |
ssize_t rc; |
808 |
|
809 |
client->recv_coroutine = qemu_coroutine_self(); |
810 |
rc = nbd_receive_request(csock, request); |
811 |
if (rc < 0) { |
812 |
if (rc != -EAGAIN) {
|
813 |
rc = -EIO; |
814 |
} |
815 |
goto out;
|
816 |
} |
817 |
|
818 |
if (request->len > NBD_BUFFER_SIZE) {
|
819 |
LOG("len (%u) is larger than max len (%u)",
|
820 |
request->len, NBD_BUFFER_SIZE); |
821 |
rc = -EINVAL; |
822 |
goto out;
|
823 |
} |
824 |
|
825 |
if ((request->from + request->len) < request->from) {
|
826 |
LOG("integer overflow detected! "
|
827 |
"you're probably being attacked");
|
828 |
rc = -EINVAL; |
829 |
goto out;
|
830 |
} |
831 |
|
832 |
TRACE("Decoding type");
|
833 |
|
834 |
if ((request->type & NBD_CMD_MASK_COMMAND) == NBD_CMD_WRITE) {
|
835 |
TRACE("Reading %u byte(s)", request->len);
|
836 |
|
837 |
if (qemu_co_recv(csock, req->data, request->len) != request->len) {
|
838 |
LOG("reading from socket failed");
|
839 |
rc = -EIO; |
840 |
goto out;
|
841 |
} |
842 |
} |
843 |
rc = 0;
|
844 |
|
845 |
out:
|
846 |
client->recv_coroutine = NULL;
|
847 |
return rc;
|
848 |
} |
849 |
|
850 |
static void nbd_trip(void *opaque) |
851 |
{ |
852 |
NBDClient *client = opaque; |
853 |
NBDExport *exp = client->exp; |
854 |
NBDRequest *req; |
855 |
struct nbd_request request;
|
856 |
struct nbd_reply reply;
|
857 |
ssize_t ret; |
858 |
|
859 |
TRACE("Reading request.");
|
860 |
if (client->closing) {
|
861 |
return;
|
862 |
} |
863 |
|
864 |
req = nbd_request_get(client); |
865 |
ret = nbd_co_receive_request(req, &request); |
866 |
if (ret == -EAGAIN) {
|
867 |
goto done;
|
868 |
} |
869 |
if (ret == -EIO) {
|
870 |
goto out;
|
871 |
} |
872 |
|
873 |
reply.handle = request.handle; |
874 |
reply.error = 0;
|
875 |
|
876 |
if (ret < 0) { |
877 |
reply.error = -ret; |
878 |
goto error_reply;
|
879 |
} |
880 |
|
881 |
if ((request.from + request.len) > exp->size) {
|
882 |
LOG("From: %" PRIu64 ", Len: %u, Size: %" PRIu64 |
883 |
", Offset: %" PRIu64 "\n", |
884 |
request.from, request.len, |
885 |
(uint64_t)exp->size, (uint64_t)exp->dev_offset); |
886 |
LOG("requested operation past EOF--bad client?");
|
887 |
goto invalid_request;
|
888 |
} |
889 |
|
890 |
switch (request.type & NBD_CMD_MASK_COMMAND) {
|
891 |
case NBD_CMD_READ:
|
892 |
TRACE("Request type is READ");
|
893 |
|
894 |
if (request.type & NBD_CMD_FLAG_FUA) {
|
895 |
ret = bdrv_co_flush(exp->bs); |
896 |
if (ret < 0) { |
897 |
LOG("flush failed");
|
898 |
reply.error = -ret; |
899 |
goto error_reply;
|
900 |
} |
901 |
} |
902 |
|
903 |
ret = bdrv_read(exp->bs, (request.from + exp->dev_offset) / 512,
|
904 |
req->data, request.len / 512);
|
905 |
if (ret < 0) { |
906 |
LOG("reading from file failed");
|
907 |
reply.error = -ret; |
908 |
goto error_reply;
|
909 |
} |
910 |
|
911 |
TRACE("Read %u byte(s)", request.len);
|
912 |
if (nbd_co_send_reply(req, &reply, request.len) < 0) |
913 |
goto out;
|
914 |
break;
|
915 |
case NBD_CMD_WRITE:
|
916 |
TRACE("Request type is WRITE");
|
917 |
|
918 |
if (exp->nbdflags & NBD_FLAG_READ_ONLY) {
|
919 |
TRACE("Server is read-only, return error");
|
920 |
reply.error = EROFS; |
921 |
goto error_reply;
|
922 |
} |
923 |
|
924 |
TRACE("Writing to device");
|
925 |
|
926 |
ret = bdrv_write(exp->bs, (request.from + exp->dev_offset) / 512,
|
927 |
req->data, request.len / 512);
|
928 |
if (ret < 0) { |
929 |
LOG("writing to file failed");
|
930 |
reply.error = -ret; |
931 |
goto error_reply;
|
932 |
} |
933 |
|
934 |
if (request.type & NBD_CMD_FLAG_FUA) {
|
935 |
ret = bdrv_co_flush(exp->bs); |
936 |
if (ret < 0) { |
937 |
LOG("flush failed");
|
938 |
reply.error = -ret; |
939 |
goto error_reply;
|
940 |
} |
941 |
} |
942 |
|
943 |
if (nbd_co_send_reply(req, &reply, 0) < 0) { |
944 |
goto out;
|
945 |
} |
946 |
break;
|
947 |
case NBD_CMD_DISC:
|
948 |
TRACE("Request type is DISCONNECT");
|
949 |
errno = 0;
|
950 |
goto out;
|
951 |
case NBD_CMD_FLUSH:
|
952 |
TRACE("Request type is FLUSH");
|
953 |
|
954 |
ret = bdrv_co_flush(exp->bs); |
955 |
if (ret < 0) { |
956 |
LOG("flush failed");
|
957 |
reply.error = -ret; |
958 |
} |
959 |
if (nbd_co_send_reply(req, &reply, 0) < 0) { |
960 |
goto out;
|
961 |
} |
962 |
break;
|
963 |
case NBD_CMD_TRIM:
|
964 |
TRACE("Request type is TRIM");
|
965 |
ret = bdrv_co_discard(exp->bs, (request.from + exp->dev_offset) / 512,
|
966 |
request.len / 512);
|
967 |
if (ret < 0) { |
968 |
LOG("discard failed");
|
969 |
reply.error = -ret; |
970 |
} |
971 |
if (nbd_co_send_reply(req, &reply, 0) < 0) { |
972 |
goto out;
|
973 |
} |
974 |
break;
|
975 |
default:
|
976 |
LOG("invalid request type (%u) received", request.type);
|
977 |
invalid_request:
|
978 |
reply.error = -EINVAL; |
979 |
error_reply:
|
980 |
if (nbd_co_send_reply(req, &reply, 0) < 0) { |
981 |
goto out;
|
982 |
} |
983 |
break;
|
984 |
} |
985 |
|
986 |
TRACE("Request/Reply complete");
|
987 |
|
988 |
done:
|
989 |
nbd_request_put(req); |
990 |
return;
|
991 |
|
992 |
out:
|
993 |
nbd_request_put(req); |
994 |
nbd_client_close(client); |
995 |
} |
996 |
|
997 |
static int nbd_can_read(void *opaque) |
998 |
{ |
999 |
NBDClient *client = opaque; |
1000 |
|
1001 |
return client->recv_coroutine || client->nb_requests < MAX_NBD_REQUESTS;
|
1002 |
} |
1003 |
|
1004 |
static void nbd_read(void *opaque) |
1005 |
{ |
1006 |
NBDClient *client = opaque; |
1007 |
|
1008 |
if (client->recv_coroutine) {
|
1009 |
qemu_coroutine_enter(client->recv_coroutine, NULL);
|
1010 |
} else {
|
1011 |
qemu_coroutine_enter(qemu_coroutine_create(nbd_trip), client); |
1012 |
} |
1013 |
} |
1014 |
|
1015 |
static void nbd_restart_write(void *opaque) |
1016 |
{ |
1017 |
NBDClient *client = opaque; |
1018 |
|
1019 |
qemu_coroutine_enter(client->send_coroutine, NULL);
|
1020 |
} |
1021 |
|
1022 |
NBDClient *nbd_client_new(NBDExport *exp, int csock,
|
1023 |
void (*close)(NBDClient *))
|
1024 |
{ |
1025 |
NBDClient *client; |
1026 |
client = g_malloc0(sizeof(NBDClient));
|
1027 |
client->refcount = 1;
|
1028 |
client->exp = exp; |
1029 |
client->sock = csock; |
1030 |
if (nbd_send_negotiate(client) < 0) { |
1031 |
g_free(client); |
1032 |
return NULL; |
1033 |
} |
1034 |
client->close = close; |
1035 |
qemu_co_mutex_init(&client->send_lock); |
1036 |
qemu_set_fd_handler2(csock, nbd_can_read, nbd_read, NULL, client);
|
1037 |
|
1038 |
nbd_export_get(exp); |
1039 |
return client;
|
1040 |
} |