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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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|
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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 |
66 |
|
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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) |
70 |
#define NBD_DO_IT _IO(0xab, 3) |
71 |
#define NBD_CLEAR_SOCK _IO(0xab, 4) |
72 |
#define NBD_CLEAR_QUE _IO(0xab, 5) |
73 |
#define NBD_PRINT_DEBUG _IO(0xab, 6) |
74 |
#define NBD_SET_SIZE_BLOCKS _IO(0xab, 7) |
75 |
#define NBD_DISCONNECT _IO(0xab, 8) |
76 |
#define NBD_SET_TIMEOUT _IO(0xab, 9) |
77 |
#define NBD_SET_FLAGS _IO(0xab, 10) |
78 |
|
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#define NBD_OPT_EXPORT_NAME (1 << 0) |
80 |
|
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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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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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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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QSIMPLEQ_HEAD(, NBDRequest) requests; |
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}; |
102 |
|
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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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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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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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128 |
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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} |
134 |
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while (offset < size) {
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ssize_t len; |
137 |
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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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} |
143 |
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if (len < 0) { |
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err = socket_error(); |
146 |
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/* recoverable error */
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if (err == EINTR || (offset > 0 && err == EAGAIN)) { |
149 |
continue;
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} |
151 |
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/* unrecoverable error */
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return -err;
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} |
155 |
|
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/* eof */
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if (len == 0) { |
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break;
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} |
160 |
|
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offset += len; |
162 |
} |
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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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} |
176 |
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static ssize_t write_sync(int fd, void *buffer, size_t size) |
178 |
{ |
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int ret;
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180 |
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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} |
186 |
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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, ":")) { |
192 |
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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} |
197 |
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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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} |
204 |
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int tcp_socket_outgoing_spec(const char *address_and_port) |
206 |
{ |
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return inet_connect(address_and_port, true, NULL, NULL); |
208 |
} |
209 |
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int tcp_socket_incoming(const char *address, uint16_t port) |
211 |
{ |
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char address_and_port[128]; |
213 |
combine_addr(address_and_port, 128, address, port);
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return tcp_socket_incoming_spec(address_and_port);
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} |
216 |
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int tcp_socket_incoming_spec(const char *address_and_port) |
218 |
{ |
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char *ostr = NULL; |
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int olen = 0; |
221 |
return inet_listen(address_and_port, ostr, olen, SOCK_STREAM, 0, NULL); |
222 |
} |
223 |
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224 |
int unix_socket_incoming(const char *path) |
225 |
{ |
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char *ostr = NULL; |
227 |
int olen = 0; |
228 |
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return unix_listen(path, ostr, olen);
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} |
231 |
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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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} |
236 |
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/* Basic flow
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Server Client
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240 |
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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) |
252 |
{ |
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int csock = client->sock;
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char buf[8 + 8 + 8 + 128]; |
255 |
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; |
267 |
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TRACE("Beginning negotiation.");
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memcpy(buf, "NBDMAGIC", 8); |
270 |
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); |
275 |
memset(buf + 28, 0, 124); |
276 |
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if (write_sync(csock, buf, sizeof(buf)) != sizeof(buf)) { |
278 |
LOG("write failed");
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goto fail;
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} |
281 |
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282 |
TRACE("Negotiation succeeded.");
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rc = 0;
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fail:
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socket_set_nonblock(csock); |
286 |
return rc;
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} |
288 |
|
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int nbd_receive_negotiate(int csock, const char *name, uint32_t *flags, |
290 |
off_t *size, size_t *blocksize) |
291 |
{ |
292 |
char buf[256]; |
293 |
uint64_t magic, s; |
294 |
uint16_t tmp; |
295 |
int rc;
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296 |
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297 |
TRACE("Receiving negotiation.");
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298 |
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299 |
socket_set_block(csock); |
300 |
rc = -EINVAL; |
301 |
|
302 |
if (read_sync(csock, buf, 8) != 8) { |
303 |
LOG("read failed");
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304 |
goto fail;
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305 |
} |
306 |
|
307 |
buf[8] = '\0'; |
308 |
if (strlen(buf) == 0) { |
309 |
LOG("server connection closed");
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310 |
goto fail;
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311 |
} |
312 |
|
313 |
TRACE("Magic is %c%c%c%c%c%c%c%c",
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314 |
qemu_isprint(buf[0]) ? buf[0] : '.', |
315 |
qemu_isprint(buf[1]) ? buf[1] : '.', |
316 |
qemu_isprint(buf[2]) ? buf[2] : '.', |
317 |
qemu_isprint(buf[3]) ? buf[3] : '.', |
318 |
qemu_isprint(buf[4]) ? buf[4] : '.', |
319 |
qemu_isprint(buf[5]) ? buf[5] : '.', |
320 |
qemu_isprint(buf[6]) ? buf[6] : '.', |
321 |
qemu_isprint(buf[7]) ? buf[7] : '.'); |
322 |
|
323 |
if (memcmp(buf, "NBDMAGIC", 8) != 0) { |
324 |
LOG("Invalid magic received");
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325 |
goto fail;
|
326 |
} |
327 |
|
328 |
if (read_sync(csock, &magic, sizeof(magic)) != sizeof(magic)) { |
329 |
LOG("read failed");
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330 |
goto fail;
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331 |
} |
332 |
magic = be64_to_cpu(magic); |
333 |
TRACE("Magic is 0x%" PRIx64, magic);
|
334 |
|
335 |
if (name) {
|
336 |
uint32_t reserved = 0;
|
337 |
uint32_t opt; |
338 |
uint32_t namesize; |
339 |
|
340 |
TRACE("Checking magic (opts_magic)");
|
341 |
if (magic != NBD_OPTS_MAGIC) {
|
342 |
LOG("Bad magic received");
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343 |
goto fail;
|
344 |
} |
345 |
if (read_sync(csock, &tmp, sizeof(tmp)) != sizeof(tmp)) { |
346 |
LOG("flags read failed");
|
347 |
goto fail;
|
348 |
} |
349 |
*flags = be16_to_cpu(tmp) << 16;
|
350 |
/* reserved for future use */
|
351 |
if (write_sync(csock, &reserved, sizeof(reserved)) != |
352 |
sizeof(reserved)) {
|
353 |
LOG("write failed (reserved)");
|
354 |
goto fail;
|
355 |
} |
356 |
/* write the export name */
|
357 |
magic = cpu_to_be64(magic); |
358 |
if (write_sync(csock, &magic, sizeof(magic)) != sizeof(magic)) { |
359 |
LOG("write failed (magic)");
|
360 |
goto fail;
|
361 |
} |
362 |
opt = cpu_to_be32(NBD_OPT_EXPORT_NAME); |
363 |
if (write_sync(csock, &opt, sizeof(opt)) != sizeof(opt)) { |
364 |
LOG("write failed (opt)");
|
365 |
goto fail;
|
366 |
} |
367 |
namesize = cpu_to_be32(strlen(name)); |
368 |
if (write_sync(csock, &namesize, sizeof(namesize)) != |
369 |
sizeof(namesize)) {
|
370 |
LOG("write failed (namesize)");
|
371 |
goto fail;
|
372 |
} |
373 |
if (write_sync(csock, (char*)name, strlen(name)) != strlen(name)) { |
374 |
LOG("write failed (name)");
|
375 |
goto fail;
|
376 |
} |
377 |
} else {
|
378 |
TRACE("Checking magic (cli_magic)");
|
379 |
|
380 |
if (magic != NBD_CLIENT_MAGIC) {
|
381 |
LOG("Bad magic received");
|
382 |
goto fail;
|
383 |
} |
384 |
} |
385 |
|
386 |
if (read_sync(csock, &s, sizeof(s)) != sizeof(s)) { |
387 |
LOG("read failed");
|
388 |
goto fail;
|
389 |
} |
390 |
*size = be64_to_cpu(s); |
391 |
*blocksize = 1024;
|
392 |
TRACE("Size is %" PRIu64, *size);
|
393 |
|
394 |
if (!name) {
|
395 |
if (read_sync(csock, flags, sizeof(*flags)) != sizeof(*flags)) { |
396 |
LOG("read failed (flags)");
|
397 |
goto fail;
|
398 |
} |
399 |
*flags = be32_to_cpup(flags); |
400 |
} else {
|
401 |
if (read_sync(csock, &tmp, sizeof(tmp)) != sizeof(tmp)) { |
402 |
LOG("read failed (tmp)");
|
403 |
goto fail;
|
404 |
} |
405 |
*flags |= be32_to_cpu(tmp); |
406 |
} |
407 |
if (read_sync(csock, &buf, 124) != 124) { |
408 |
LOG("read failed (buf)");
|
409 |
goto fail;
|
410 |
} |
411 |
rc = 0;
|
412 |
|
413 |
fail:
|
414 |
socket_set_nonblock(csock); |
415 |
return rc;
|
416 |
} |
417 |
|
418 |
#ifdef __linux__
|
419 |
int nbd_init(int fd, int csock, uint32_t flags, off_t size, size_t blocksize) |
420 |
{ |
421 |
TRACE("Setting NBD socket");
|
422 |
|
423 |
if (ioctl(fd, NBD_SET_SOCK, csock) < 0) { |
424 |
int serrno = errno;
|
425 |
LOG("Failed to set NBD socket");
|
426 |
return -serrno;
|
427 |
} |
428 |
|
429 |
TRACE("Setting block size to %lu", (unsigned long)blocksize); |
430 |
|
431 |
if (ioctl(fd, NBD_SET_BLKSIZE, blocksize) < 0) { |
432 |
int serrno = errno;
|
433 |
LOG("Failed setting NBD block size");
|
434 |
return -serrno;
|
435 |
} |
436 |
|
437 |
TRACE("Setting size to %zd block(s)", (size_t)(size / blocksize));
|
438 |
|
439 |
if (ioctl(fd, NBD_SET_SIZE_BLOCKS, size / blocksize) < 0) { |
440 |
int serrno = errno;
|
441 |
LOG("Failed setting size (in blocks)");
|
442 |
return -serrno;
|
443 |
} |
444 |
|
445 |
if (flags & NBD_FLAG_READ_ONLY) {
|
446 |
int read_only = 1; |
447 |
TRACE("Setting readonly attribute");
|
448 |
|
449 |
if (ioctl(fd, BLKROSET, (unsigned long) &read_only) < 0) { |
450 |
int serrno = errno;
|
451 |
LOG("Failed setting read-only attribute");
|
452 |
return -serrno;
|
453 |
} |
454 |
} |
455 |
|
456 |
if (ioctl(fd, NBD_SET_FLAGS, flags) < 0 |
457 |
&& errno != ENOTTY) { |
458 |
int serrno = errno;
|
459 |
LOG("Failed setting flags");
|
460 |
return -serrno;
|
461 |
} |
462 |
|
463 |
TRACE("Negotiation ended");
|
464 |
|
465 |
return 0; |
466 |
} |
467 |
|
468 |
int nbd_disconnect(int fd) |
469 |
{ |
470 |
ioctl(fd, NBD_CLEAR_QUE); |
471 |
ioctl(fd, NBD_DISCONNECT); |
472 |
ioctl(fd, NBD_CLEAR_SOCK); |
473 |
return 0; |
474 |
} |
475 |
|
476 |
int nbd_client(int fd) |
477 |
{ |
478 |
int ret;
|
479 |
int serrno;
|
480 |
|
481 |
TRACE("Doing NBD loop");
|
482 |
|
483 |
ret = ioctl(fd, NBD_DO_IT); |
484 |
if (ret < 0 && errno == EPIPE) { |
485 |
/* NBD_DO_IT normally returns EPIPE when someone has disconnected
|
486 |
* the socket via NBD_DISCONNECT. We do not want to return 1 in
|
487 |
* that case.
|
488 |
*/
|
489 |
ret = 0;
|
490 |
} |
491 |
serrno = errno; |
492 |
|
493 |
TRACE("NBD loop returned %d: %s", ret, strerror(serrno));
|
494 |
|
495 |
TRACE("Clearing NBD queue");
|
496 |
ioctl(fd, NBD_CLEAR_QUE); |
497 |
|
498 |
TRACE("Clearing NBD socket");
|
499 |
ioctl(fd, NBD_CLEAR_SOCK); |
500 |
|
501 |
errno = serrno; |
502 |
return ret;
|
503 |
} |
504 |
#else
|
505 |
int nbd_init(int fd, int csock, uint32_t flags, off_t size, size_t blocksize) |
506 |
{ |
507 |
return -ENOTSUP;
|
508 |
} |
509 |
|
510 |
int nbd_disconnect(int fd) |
511 |
{ |
512 |
return -ENOTSUP;
|
513 |
} |
514 |
|
515 |
int nbd_client(int fd) |
516 |
{ |
517 |
return -ENOTSUP;
|
518 |
} |
519 |
#endif
|
520 |
|
521 |
ssize_t nbd_send_request(int csock, struct nbd_request *request) |
522 |
{ |
523 |
uint8_t buf[NBD_REQUEST_SIZE]; |
524 |
ssize_t ret; |
525 |
|
526 |
cpu_to_be32w((uint32_t*)buf, NBD_REQUEST_MAGIC); |
527 |
cpu_to_be32w((uint32_t*)(buf + 4), request->type);
|
528 |
cpu_to_be64w((uint64_t*)(buf + 8), request->handle);
|
529 |
cpu_to_be64w((uint64_t*)(buf + 16), request->from);
|
530 |
cpu_to_be32w((uint32_t*)(buf + 24), request->len);
|
531 |
|
532 |
TRACE("Sending request to client: "
|
533 |
"{ .from = %" PRIu64", .len = %u, .handle = %" PRIu64", .type=%i}", |
534 |
request->from, request->len, request->handle, request->type); |
535 |
|
536 |
ret = write_sync(csock, buf, sizeof(buf));
|
537 |
if (ret < 0) { |
538 |
return ret;
|
539 |
} |
540 |
|
541 |
if (ret != sizeof(buf)) { |
542 |
LOG("writing to socket failed");
|
543 |
return -EINVAL;
|
544 |
} |
545 |
return 0; |
546 |
} |
547 |
|
548 |
static ssize_t nbd_receive_request(int csock, struct nbd_request *request) |
549 |
{ |
550 |
uint8_t buf[NBD_REQUEST_SIZE]; |
551 |
uint32_t magic; |
552 |
ssize_t ret; |
553 |
|
554 |
ret = read_sync(csock, buf, sizeof(buf));
|
555 |
if (ret < 0) { |
556 |
return ret;
|
557 |
} |
558 |
|
559 |
if (ret != sizeof(buf)) { |
560 |
LOG("read failed");
|
561 |
return -EINVAL;
|
562 |
} |
563 |
|
564 |
/* Request
|
565 |
[ 0 .. 3] magic (NBD_REQUEST_MAGIC)
|
566 |
[ 4 .. 7] type (0 == READ, 1 == WRITE)
|
567 |
[ 8 .. 15] handle
|
568 |
[16 .. 23] from
|
569 |
[24 .. 27] len
|
570 |
*/
|
571 |
|
572 |
magic = be32_to_cpup((uint32_t*)buf); |
573 |
request->type = be32_to_cpup((uint32_t*)(buf + 4));
|
574 |
request->handle = be64_to_cpup((uint64_t*)(buf + 8));
|
575 |
request->from = be64_to_cpup((uint64_t*)(buf + 16));
|
576 |
request->len = be32_to_cpup((uint32_t*)(buf + 24));
|
577 |
|
578 |
TRACE("Got request: "
|
579 |
"{ magic = 0x%x, .type = %d, from = %" PRIu64" , len = %u }", |
580 |
magic, request->type, request->from, request->len); |
581 |
|
582 |
if (magic != NBD_REQUEST_MAGIC) {
|
583 |
LOG("invalid magic (got 0x%x)", magic);
|
584 |
return -EINVAL;
|
585 |
} |
586 |
return 0; |
587 |
} |
588 |
|
589 |
ssize_t nbd_receive_reply(int csock, struct nbd_reply *reply) |
590 |
{ |
591 |
uint8_t buf[NBD_REPLY_SIZE]; |
592 |
uint32_t magic; |
593 |
ssize_t ret; |
594 |
|
595 |
ret = read_sync(csock, buf, sizeof(buf));
|
596 |
if (ret < 0) { |
597 |
return ret;
|
598 |
} |
599 |
|
600 |
if (ret != sizeof(buf)) { |
601 |
LOG("read failed");
|
602 |
return -EINVAL;
|
603 |
} |
604 |
|
605 |
/* Reply
|
606 |
[ 0 .. 3] magic (NBD_REPLY_MAGIC)
|
607 |
[ 4 .. 7] error (0 == no error)
|
608 |
[ 7 .. 15] handle
|
609 |
*/
|
610 |
|
611 |
magic = be32_to_cpup((uint32_t*)buf); |
612 |
reply->error = be32_to_cpup((uint32_t*)(buf + 4));
|
613 |
reply->handle = be64_to_cpup((uint64_t*)(buf + 8));
|
614 |
|
615 |
TRACE("Got reply: "
|
616 |
"{ magic = 0x%x, .error = %d, handle = %" PRIu64" }", |
617 |
magic, reply->error, reply->handle); |
618 |
|
619 |
if (magic != NBD_REPLY_MAGIC) {
|
620 |
LOG("invalid magic (got 0x%x)", magic);
|
621 |
return -EINVAL;
|
622 |
} |
623 |
return 0; |
624 |
} |
625 |
|
626 |
static ssize_t nbd_send_reply(int csock, struct nbd_reply *reply) |
627 |
{ |
628 |
uint8_t buf[NBD_REPLY_SIZE]; |
629 |
ssize_t ret; |
630 |
|
631 |
/* Reply
|
632 |
[ 0 .. 3] magic (NBD_REPLY_MAGIC)
|
633 |
[ 4 .. 7] error (0 == no error)
|
634 |
[ 7 .. 15] handle
|
635 |
*/
|
636 |
cpu_to_be32w((uint32_t*)buf, NBD_REPLY_MAGIC); |
637 |
cpu_to_be32w((uint32_t*)(buf + 4), reply->error);
|
638 |
cpu_to_be64w((uint64_t*)(buf + 8), reply->handle);
|
639 |
|
640 |
TRACE("Sending response to client");
|
641 |
|
642 |
ret = write_sync(csock, buf, sizeof(buf));
|
643 |
if (ret < 0) { |
644 |
return ret;
|
645 |
} |
646 |
|
647 |
if (ret != sizeof(buf)) { |
648 |
LOG("writing to socket failed");
|
649 |
return -EINVAL;
|
650 |
} |
651 |
return 0; |
652 |
} |
653 |
|
654 |
#define MAX_NBD_REQUESTS 16 |
655 |
|
656 |
void nbd_client_get(NBDClient *client)
|
657 |
{ |
658 |
client->refcount++; |
659 |
} |
660 |
|
661 |
void nbd_client_put(NBDClient *client)
|
662 |
{ |
663 |
if (--client->refcount == 0) { |
664 |
/* The last reference should be dropped by client->close,
|
665 |
* which is called by nbd_client_close.
|
666 |
*/
|
667 |
assert(client->closing); |
668 |
|
669 |
qemu_set_fd_handler2(client->sock, NULL, NULL, NULL, NULL); |
670 |
close(client->sock); |
671 |
client->sock = -1;
|
672 |
QTAILQ_REMOVE(&client->exp->clients, client, next); |
673 |
nbd_export_put(client->exp); |
674 |
g_free(client); |
675 |
} |
676 |
} |
677 |
|
678 |
void nbd_client_close(NBDClient *client)
|
679 |
{ |
680 |
if (client->closing) {
|
681 |
return;
|
682 |
} |
683 |
|
684 |
client->closing = true;
|
685 |
|
686 |
/* Force requests to finish. They will drop their own references,
|
687 |
* then we'll close the socket and free the NBDClient.
|
688 |
*/
|
689 |
shutdown(client->sock, 2);
|
690 |
|
691 |
/* Also tell the client, so that they release their reference. */
|
692 |
if (client->close) {
|
693 |
client->close(client); |
694 |
} |
695 |
} |
696 |
|
697 |
static NBDRequest *nbd_request_get(NBDClient *client)
|
698 |
{ |
699 |
NBDRequest *req; |
700 |
NBDExport *exp = client->exp; |
701 |
|
702 |
assert(client->nb_requests <= MAX_NBD_REQUESTS - 1);
|
703 |
client->nb_requests++; |
704 |
|
705 |
if (QSIMPLEQ_EMPTY(&exp->requests)) {
|
706 |
req = g_malloc0(sizeof(NBDRequest));
|
707 |
req->data = qemu_blockalign(exp->bs, NBD_BUFFER_SIZE); |
708 |
} else {
|
709 |
req = QSIMPLEQ_FIRST(&exp->requests); |
710 |
QSIMPLEQ_REMOVE_HEAD(&exp->requests, entry); |
711 |
} |
712 |
nbd_client_get(client); |
713 |
req->client = client; |
714 |
return req;
|
715 |
} |
716 |
|
717 |
static void nbd_request_put(NBDRequest *req) |
718 |
{ |
719 |
NBDClient *client = req->client; |
720 |
QSIMPLEQ_INSERT_HEAD(&client->exp->requests, req, entry); |
721 |
if (client->nb_requests-- == MAX_NBD_REQUESTS) {
|
722 |
qemu_notify_event(); |
723 |
} |
724 |
nbd_client_put(client); |
725 |
} |
726 |
|
727 |
NBDExport *nbd_export_new(BlockDriverState *bs, off_t dev_offset, |
728 |
off_t size, uint32_t nbdflags, |
729 |
void (*close)(NBDExport *))
|
730 |
{ |
731 |
NBDExport *exp = g_malloc0(sizeof(NBDExport));
|
732 |
QSIMPLEQ_INIT(&exp->requests); |
733 |
exp->refcount = 1;
|
734 |
QTAILQ_INIT(&exp->clients); |
735 |
exp->bs = bs; |
736 |
exp->dev_offset = dev_offset; |
737 |
exp->nbdflags = nbdflags; |
738 |
exp->size = size == -1 ? bdrv_getlength(bs) : size;
|
739 |
exp->close = close; |
740 |
return exp;
|
741 |
} |
742 |
|
743 |
void nbd_export_close(NBDExport *exp)
|
744 |
{ |
745 |
NBDClient *client, *next; |
746 |
|
747 |
nbd_export_get(exp); |
748 |
QTAILQ_FOREACH_SAFE(client, &exp->clients, next, next) { |
749 |
nbd_client_close(client); |
750 |
} |
751 |
nbd_export_put(exp); |
752 |
} |
753 |
|
754 |
void nbd_export_get(NBDExport *exp)
|
755 |
{ |
756 |
assert(exp->refcount > 0);
|
757 |
exp->refcount++; |
758 |
} |
759 |
|
760 |
void nbd_export_put(NBDExport *exp)
|
761 |
{ |
762 |
assert(exp->refcount > 0);
|
763 |
if (exp->refcount == 1) { |
764 |
nbd_export_close(exp); |
765 |
} |
766 |
|
767 |
if (--exp->refcount == 0) { |
768 |
if (exp->close) {
|
769 |
exp->close(exp); |
770 |
} |
771 |
|
772 |
while (!QSIMPLEQ_EMPTY(&exp->requests)) {
|
773 |
NBDRequest *first = QSIMPLEQ_FIRST(&exp->requests); |
774 |
QSIMPLEQ_REMOVE_HEAD(&exp->requests, entry); |
775 |
qemu_vfree(first->data); |
776 |
g_free(first); |
777 |
} |
778 |
|
779 |
g_free(exp); |
780 |
} |
781 |
} |
782 |
|
783 |
static int nbd_can_read(void *opaque); |
784 |
static void nbd_read(void *opaque); |
785 |
static void nbd_restart_write(void *opaque); |
786 |
|
787 |
static ssize_t nbd_co_send_reply(NBDRequest *req, struct nbd_reply *reply, |
788 |
int len)
|
789 |
{ |
790 |
NBDClient *client = req->client; |
791 |
int csock = client->sock;
|
792 |
ssize_t rc, ret; |
793 |
|
794 |
qemu_co_mutex_lock(&client->send_lock); |
795 |
qemu_set_fd_handler2(csock, nbd_can_read, nbd_read, |
796 |
nbd_restart_write, client); |
797 |
client->send_coroutine = qemu_coroutine_self(); |
798 |
|
799 |
if (!len) {
|
800 |
rc = nbd_send_reply(csock, reply); |
801 |
} else {
|
802 |
socket_set_cork(csock, 1);
|
803 |
rc = nbd_send_reply(csock, reply); |
804 |
if (rc >= 0) { |
805 |
ret = qemu_co_send(csock, req->data, len); |
806 |
if (ret != len) {
|
807 |
rc = -EIO; |
808 |
} |
809 |
} |
810 |
socket_set_cork(csock, 0);
|
811 |
} |
812 |
|
813 |
client->send_coroutine = NULL;
|
814 |
qemu_set_fd_handler2(csock, nbd_can_read, nbd_read, NULL, client);
|
815 |
qemu_co_mutex_unlock(&client->send_lock); |
816 |
return rc;
|
817 |
} |
818 |
|
819 |
static ssize_t nbd_co_receive_request(NBDRequest *req, struct nbd_request *request) |
820 |
{ |
821 |
NBDClient *client = req->client; |
822 |
int csock = client->sock;
|
823 |
ssize_t rc; |
824 |
|
825 |
client->recv_coroutine = qemu_coroutine_self(); |
826 |
rc = nbd_receive_request(csock, request); |
827 |
if (rc < 0) { |
828 |
if (rc != -EAGAIN) {
|
829 |
rc = -EIO; |
830 |
} |
831 |
goto out;
|
832 |
} |
833 |
|
834 |
if (request->len > NBD_BUFFER_SIZE) {
|
835 |
LOG("len (%u) is larger than max len (%u)",
|
836 |
request->len, NBD_BUFFER_SIZE); |
837 |
rc = -EINVAL; |
838 |
goto out;
|
839 |
} |
840 |
|
841 |
if ((request->from + request->len) < request->from) {
|
842 |
LOG("integer overflow detected! "
|
843 |
"you're probably being attacked");
|
844 |
rc = -EINVAL; |
845 |
goto out;
|
846 |
} |
847 |
|
848 |
TRACE("Decoding type");
|
849 |
|
850 |
if ((request->type & NBD_CMD_MASK_COMMAND) == NBD_CMD_WRITE) {
|
851 |
TRACE("Reading %u byte(s)", request->len);
|
852 |
|
853 |
if (qemu_co_recv(csock, req->data, request->len) != request->len) {
|
854 |
LOG("reading from socket failed");
|
855 |
rc = -EIO; |
856 |
goto out;
|
857 |
} |
858 |
} |
859 |
rc = 0;
|
860 |
|
861 |
out:
|
862 |
client->recv_coroutine = NULL;
|
863 |
return rc;
|
864 |
} |
865 |
|
866 |
static void nbd_trip(void *opaque) |
867 |
{ |
868 |
NBDClient *client = opaque; |
869 |
NBDExport *exp = client->exp; |
870 |
NBDRequest *req; |
871 |
struct nbd_request request;
|
872 |
struct nbd_reply reply;
|
873 |
ssize_t ret; |
874 |
|
875 |
TRACE("Reading request.");
|
876 |
if (client->closing) {
|
877 |
return;
|
878 |
} |
879 |
|
880 |
req = nbd_request_get(client); |
881 |
ret = nbd_co_receive_request(req, &request); |
882 |
if (ret == -EAGAIN) {
|
883 |
goto done;
|
884 |
} |
885 |
if (ret == -EIO) {
|
886 |
goto out;
|
887 |
} |
888 |
|
889 |
reply.handle = request.handle; |
890 |
reply.error = 0;
|
891 |
|
892 |
if (ret < 0) { |
893 |
reply.error = -ret; |
894 |
goto error_reply;
|
895 |
} |
896 |
|
897 |
if ((request.from + request.len) > exp->size) {
|
898 |
LOG("From: %" PRIu64 ", Len: %u, Size: %" PRIu64 |
899 |
", Offset: %" PRIu64 "\n", |
900 |
request.from, request.len, |
901 |
(uint64_t)exp->size, (uint64_t)exp->dev_offset); |
902 |
LOG("requested operation past EOF--bad client?");
|
903 |
goto invalid_request;
|
904 |
} |
905 |
|
906 |
switch (request.type & NBD_CMD_MASK_COMMAND) {
|
907 |
case NBD_CMD_READ:
|
908 |
TRACE("Request type is READ");
|
909 |
|
910 |
if (request.type & NBD_CMD_FLAG_FUA) {
|
911 |
ret = bdrv_co_flush(exp->bs); |
912 |
if (ret < 0) { |
913 |
LOG("flush failed");
|
914 |
reply.error = -ret; |
915 |
goto error_reply;
|
916 |
} |
917 |
} |
918 |
|
919 |
ret = bdrv_read(exp->bs, (request.from + exp->dev_offset) / 512,
|
920 |
req->data, request.len / 512);
|
921 |
if (ret < 0) { |
922 |
LOG("reading from file failed");
|
923 |
reply.error = -ret; |
924 |
goto error_reply;
|
925 |
} |
926 |
|
927 |
TRACE("Read %u byte(s)", request.len);
|
928 |
if (nbd_co_send_reply(req, &reply, request.len) < 0) |
929 |
goto out;
|
930 |
break;
|
931 |
case NBD_CMD_WRITE:
|
932 |
TRACE("Request type is WRITE");
|
933 |
|
934 |
if (exp->nbdflags & NBD_FLAG_READ_ONLY) {
|
935 |
TRACE("Server is read-only, return error");
|
936 |
reply.error = EROFS; |
937 |
goto error_reply;
|
938 |
} |
939 |
|
940 |
TRACE("Writing to device");
|
941 |
|
942 |
ret = bdrv_write(exp->bs, (request.from + exp->dev_offset) / 512,
|
943 |
req->data, request.len / 512);
|
944 |
if (ret < 0) { |
945 |
LOG("writing to file failed");
|
946 |
reply.error = -ret; |
947 |
goto error_reply;
|
948 |
} |
949 |
|
950 |
if (request.type & NBD_CMD_FLAG_FUA) {
|
951 |
ret = bdrv_co_flush(exp->bs); |
952 |
if (ret < 0) { |
953 |
LOG("flush failed");
|
954 |
reply.error = -ret; |
955 |
goto error_reply;
|
956 |
} |
957 |
} |
958 |
|
959 |
if (nbd_co_send_reply(req, &reply, 0) < 0) { |
960 |
goto out;
|
961 |
} |
962 |
break;
|
963 |
case NBD_CMD_DISC:
|
964 |
TRACE("Request type is DISCONNECT");
|
965 |
errno = 0;
|
966 |
goto out;
|
967 |
case NBD_CMD_FLUSH:
|
968 |
TRACE("Request type is FLUSH");
|
969 |
|
970 |
ret = bdrv_co_flush(exp->bs); |
971 |
if (ret < 0) { |
972 |
LOG("flush failed");
|
973 |
reply.error = -ret; |
974 |
} |
975 |
if (nbd_co_send_reply(req, &reply, 0) < 0) { |
976 |
goto out;
|
977 |
} |
978 |
break;
|
979 |
case NBD_CMD_TRIM:
|
980 |
TRACE("Request type is TRIM");
|
981 |
ret = bdrv_co_discard(exp->bs, (request.from + exp->dev_offset) / 512,
|
982 |
request.len / 512);
|
983 |
if (ret < 0) { |
984 |
LOG("discard failed");
|
985 |
reply.error = -ret; |
986 |
} |
987 |
if (nbd_co_send_reply(req, &reply, 0) < 0) { |
988 |
goto out;
|
989 |
} |
990 |
break;
|
991 |
default:
|
992 |
LOG("invalid request type (%u) received", request.type);
|
993 |
invalid_request:
|
994 |
reply.error = -EINVAL; |
995 |
error_reply:
|
996 |
if (nbd_co_send_reply(req, &reply, 0) < 0) { |
997 |
goto out;
|
998 |
} |
999 |
break;
|
1000 |
} |
1001 |
|
1002 |
TRACE("Request/Reply complete");
|
1003 |
|
1004 |
done:
|
1005 |
nbd_request_put(req); |
1006 |
return;
|
1007 |
|
1008 |
out:
|
1009 |
nbd_request_put(req); |
1010 |
nbd_client_close(client); |
1011 |
} |
1012 |
|
1013 |
static int nbd_can_read(void *opaque) |
1014 |
{ |
1015 |
NBDClient *client = opaque; |
1016 |
|
1017 |
return client->recv_coroutine || client->nb_requests < MAX_NBD_REQUESTS;
|
1018 |
} |
1019 |
|
1020 |
static void nbd_read(void *opaque) |
1021 |
{ |
1022 |
NBDClient *client = opaque; |
1023 |
|
1024 |
if (client->recv_coroutine) {
|
1025 |
qemu_coroutine_enter(client->recv_coroutine, NULL);
|
1026 |
} else {
|
1027 |
qemu_coroutine_enter(qemu_coroutine_create(nbd_trip), client); |
1028 |
} |
1029 |
} |
1030 |
|
1031 |
static void nbd_restart_write(void *opaque) |
1032 |
{ |
1033 |
NBDClient *client = opaque; |
1034 |
|
1035 |
qemu_coroutine_enter(client->send_coroutine, NULL);
|
1036 |
} |
1037 |
|
1038 |
NBDClient *nbd_client_new(NBDExport *exp, int csock,
|
1039 |
void (*close)(NBDClient *))
|
1040 |
{ |
1041 |
NBDClient *client; |
1042 |
client = g_malloc0(sizeof(NBDClient));
|
1043 |
client->refcount = 1;
|
1044 |
client->exp = exp; |
1045 |
client->sock = csock; |
1046 |
if (nbd_send_negotiate(client) < 0) { |
1047 |
g_free(client); |
1048 |
return NULL; |
1049 |
} |
1050 |
client->close = close; |
1051 |
qemu_co_mutex_init(&client->send_lock); |
1052 |
qemu_set_fd_handler2(csock, nbd_can_read, nbd_read, NULL, client);
|
1053 |
|
1054 |
QTAILQ_INSERT_TAIL(&exp->clients, client, next); |
1055 |
nbd_export_get(exp); |
1056 |
return client;
|
1057 |
} |