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/*
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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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|
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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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void (*close)(NBDExport *exp);
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|
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BlockDriverState *bs; |
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char *name;
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off_t dev_offset; |
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off_t size; |
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uint32_t nbdflags; |
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QTAILQ_HEAD(, NBDClient) clients; |
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QSIMPLEQ_HEAD(, NBDRequest) requests; |
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QTAILQ_ENTRY(NBDExport) next; |
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}; |
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static QTAILQ_HEAD(, NBDExport) exports = QTAILQ_HEAD_INITIALIZER(exports);
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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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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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/* 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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} |
138 |
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while (offset < size) {
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ssize_t len; |
141 |
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if (do_read) {
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len = qemu_recv(fd, buffer + offset, size - offset, 0);
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} else {
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len = send(fd, buffer + offset, size - offset, 0);
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} |
147 |
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if (len < 0) { |
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err = socket_error(); |
150 |
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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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} |
155 |
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/* unrecoverable error */
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return -err;
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} |
159 |
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/* eof */
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if (len == 0) { |
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break;
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} |
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offset += len; |
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} |
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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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} |
180 |
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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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} |
190 |
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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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} |
201 |
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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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} |
208 |
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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); |
212 |
} |
213 |
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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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} |
220 |
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int tcp_socket_incoming_spec(const char *address_and_port) |
222 |
{ |
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char *ostr = NULL; |
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int olen = 0; |
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return inet_listen(address_and_port, ostr, olen, SOCK_STREAM, 0, NULL); |
226 |
} |
227 |
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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; |
232 |
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return unix_listen(path, ostr, olen);
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} |
235 |
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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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} |
240 |
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/* Basic flow for negotiation
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Server Client
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Negotiate
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or
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Server Client
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Negotiate #1
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Option
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Negotiate #2
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----
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followed by
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Server Client
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Request
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Response
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Request
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Response
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...
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...
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Request (type == 2)
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*/
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267 |
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static int nbd_receive_options(NBDClient *client) |
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{ |
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int csock = client->sock;
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char name[256]; |
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uint32_t tmp, length; |
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uint64_t magic; |
274 |
int rc;
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275 |
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/* Client sends:
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[ 0 .. 3] reserved (0)
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[ 4 .. 11] NBD_OPTS_MAGIC
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[12 .. 15] NBD_OPT_EXPORT_NAME
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[16 .. 19] length
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[20 .. xx] export name (length bytes)
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*/
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283 |
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rc = -EINVAL; |
285 |
if (read_sync(csock, &tmp, sizeof(tmp)) != sizeof(tmp)) { |
286 |
LOG("read failed");
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goto fail;
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288 |
} |
289 |
TRACE("Checking reserved");
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if (tmp != 0) { |
291 |
LOG("Bad reserved received");
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goto fail;
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293 |
} |
294 |
|
295 |
if (read_sync(csock, &magic, sizeof(magic)) != sizeof(magic)) { |
296 |
LOG("read failed");
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goto fail;
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298 |
} |
299 |
TRACE("Checking reserved");
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300 |
if (magic != be64_to_cpu(NBD_OPTS_MAGIC)) {
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301 |
LOG("Bad magic received");
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302 |
goto fail;
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303 |
} |
304 |
|
305 |
if (read_sync(csock, &tmp, sizeof(tmp)) != sizeof(tmp)) { |
306 |
LOG("read failed");
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307 |
goto fail;
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308 |
} |
309 |
TRACE("Checking option");
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310 |
if (tmp != be32_to_cpu(NBD_OPT_EXPORT_NAME)) {
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311 |
LOG("Bad option received");
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312 |
goto fail;
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313 |
} |
314 |
|
315 |
if (read_sync(csock, &length, sizeof(length)) != sizeof(length)) { |
316 |
LOG("read failed");
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317 |
goto fail;
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318 |
} |
319 |
TRACE("Checking length");
|
320 |
length = be32_to_cpu(length); |
321 |
if (length > 255) { |
322 |
LOG("Bad length received");
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323 |
goto fail;
|
324 |
} |
325 |
if (read_sync(csock, name, length) != length) {
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326 |
LOG("read failed");
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327 |
goto fail;
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328 |
} |
329 |
name[length] = '\0';
|
330 |
|
331 |
client->exp = nbd_export_find(name); |
332 |
if (!client->exp) {
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333 |
LOG("export not found");
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334 |
goto fail;
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335 |
} |
336 |
|
337 |
QTAILQ_INSERT_TAIL(&client->exp->clients, client, next); |
338 |
nbd_export_get(client->exp); |
339 |
|
340 |
TRACE("Option negotiation succeeded.");
|
341 |
rc = 0;
|
342 |
fail:
|
343 |
return rc;
|
344 |
} |
345 |
|
346 |
static int nbd_send_negotiate(NBDClient *client) |
347 |
{ |
348 |
int csock = client->sock;
|
349 |
char buf[8 + 8 + 8 + 128]; |
350 |
int rc;
|
351 |
const int myflags = (NBD_FLAG_HAS_FLAGS | NBD_FLAG_SEND_TRIM | |
352 |
NBD_FLAG_SEND_FLUSH | NBD_FLAG_SEND_FUA); |
353 |
|
354 |
/* Negotiation header without options:
|
355 |
[ 0 .. 7] passwd ("NBDMAGIC")
|
356 |
[ 8 .. 15] magic (NBD_CLIENT_MAGIC)
|
357 |
[16 .. 23] size
|
358 |
[24 .. 25] server flags (0)
|
359 |
[24 .. 27] export flags
|
360 |
[28 .. 151] reserved (0)
|
361 |
|
362 |
Negotiation header with options, part 1:
|
363 |
[ 0 .. 7] passwd ("NBDMAGIC")
|
364 |
[ 8 .. 15] magic (NBD_OPTS_MAGIC)
|
365 |
[16 .. 17] server flags (0)
|
366 |
|
367 |
part 2 (after options are sent):
|
368 |
[18 .. 25] size
|
369 |
[26 .. 27] export flags
|
370 |
[28 .. 151] reserved (0)
|
371 |
*/
|
372 |
|
373 |
socket_set_block(csock); |
374 |
rc = -EINVAL; |
375 |
|
376 |
TRACE("Beginning negotiation.");
|
377 |
memcpy(buf, "NBDMAGIC", 8); |
378 |
if (client->exp) {
|
379 |
assert ((client->exp->nbdflags & ~65535) == 0); |
380 |
cpu_to_be64w((uint64_t*)(buf + 8), NBD_CLIENT_MAGIC);
|
381 |
cpu_to_be64w((uint64_t*)(buf + 16), client->exp->size);
|
382 |
cpu_to_be16w((uint16_t*)(buf + 26), client->exp->nbdflags | myflags);
|
383 |
} else {
|
384 |
cpu_to_be64w((uint64_t*)(buf + 8), NBD_OPTS_MAGIC);
|
385 |
} |
386 |
memset(buf + 28, 0, 124); |
387 |
|
388 |
if (client->exp) {
|
389 |
if (write_sync(csock, buf, sizeof(buf)) != sizeof(buf)) { |
390 |
LOG("write failed");
|
391 |
goto fail;
|
392 |
} |
393 |
} else {
|
394 |
if (write_sync(csock, buf, 18) != 18) { |
395 |
LOG("write failed");
|
396 |
goto fail;
|
397 |
} |
398 |
rc = nbd_receive_options(client); |
399 |
if (rc < 0) { |
400 |
LOG("option negotiation failed");
|
401 |
goto fail;
|
402 |
} |
403 |
|
404 |
assert ((client->exp->nbdflags & ~65535) == 0); |
405 |
cpu_to_be64w((uint64_t*)(buf + 18), client->exp->size);
|
406 |
cpu_to_be16w((uint16_t*)(buf + 26), client->exp->nbdflags | myflags);
|
407 |
if (write_sync(csock, buf + 18, sizeof(buf) - 18) != sizeof(buf) - 18) { |
408 |
LOG("write failed");
|
409 |
goto fail;
|
410 |
} |
411 |
} |
412 |
|
413 |
TRACE("Negotiation succeeded.");
|
414 |
rc = 0;
|
415 |
fail:
|
416 |
socket_set_nonblock(csock); |
417 |
return rc;
|
418 |
} |
419 |
|
420 |
int nbd_receive_negotiate(int csock, const char *name, uint32_t *flags, |
421 |
off_t *size, size_t *blocksize) |
422 |
{ |
423 |
char buf[256]; |
424 |
uint64_t magic, s; |
425 |
uint16_t tmp; |
426 |
int rc;
|
427 |
|
428 |
TRACE("Receiving negotiation.");
|
429 |
|
430 |
socket_set_block(csock); |
431 |
rc = -EINVAL; |
432 |
|
433 |
if (read_sync(csock, buf, 8) != 8) { |
434 |
LOG("read failed");
|
435 |
goto fail;
|
436 |
} |
437 |
|
438 |
buf[8] = '\0'; |
439 |
if (strlen(buf) == 0) { |
440 |
LOG("server connection closed");
|
441 |
goto fail;
|
442 |
} |
443 |
|
444 |
TRACE("Magic is %c%c%c%c%c%c%c%c",
|
445 |
qemu_isprint(buf[0]) ? buf[0] : '.', |
446 |
qemu_isprint(buf[1]) ? buf[1] : '.', |
447 |
qemu_isprint(buf[2]) ? buf[2] : '.', |
448 |
qemu_isprint(buf[3]) ? buf[3] : '.', |
449 |
qemu_isprint(buf[4]) ? buf[4] : '.', |
450 |
qemu_isprint(buf[5]) ? buf[5] : '.', |
451 |
qemu_isprint(buf[6]) ? buf[6] : '.', |
452 |
qemu_isprint(buf[7]) ? buf[7] : '.'); |
453 |
|
454 |
if (memcmp(buf, "NBDMAGIC", 8) != 0) { |
455 |
LOG("Invalid magic received");
|
456 |
goto fail;
|
457 |
} |
458 |
|
459 |
if (read_sync(csock, &magic, sizeof(magic)) != sizeof(magic)) { |
460 |
LOG("read failed");
|
461 |
goto fail;
|
462 |
} |
463 |
magic = be64_to_cpu(magic); |
464 |
TRACE("Magic is 0x%" PRIx64, magic);
|
465 |
|
466 |
if (name) {
|
467 |
uint32_t reserved = 0;
|
468 |
uint32_t opt; |
469 |
uint32_t namesize; |
470 |
|
471 |
TRACE("Checking magic (opts_magic)");
|
472 |
if (magic != NBD_OPTS_MAGIC) {
|
473 |
LOG("Bad magic received");
|
474 |
goto fail;
|
475 |
} |
476 |
if (read_sync(csock, &tmp, sizeof(tmp)) != sizeof(tmp)) { |
477 |
LOG("flags read failed");
|
478 |
goto fail;
|
479 |
} |
480 |
*flags = be16_to_cpu(tmp) << 16;
|
481 |
/* reserved for future use */
|
482 |
if (write_sync(csock, &reserved, sizeof(reserved)) != |
483 |
sizeof(reserved)) {
|
484 |
LOG("write failed (reserved)");
|
485 |
goto fail;
|
486 |
} |
487 |
/* write the export name */
|
488 |
magic = cpu_to_be64(magic); |
489 |
if (write_sync(csock, &magic, sizeof(magic)) != sizeof(magic)) { |
490 |
LOG("write failed (magic)");
|
491 |
goto fail;
|
492 |
} |
493 |
opt = cpu_to_be32(NBD_OPT_EXPORT_NAME); |
494 |
if (write_sync(csock, &opt, sizeof(opt)) != sizeof(opt)) { |
495 |
LOG("write failed (opt)");
|
496 |
goto fail;
|
497 |
} |
498 |
namesize = cpu_to_be32(strlen(name)); |
499 |
if (write_sync(csock, &namesize, sizeof(namesize)) != |
500 |
sizeof(namesize)) {
|
501 |
LOG("write failed (namesize)");
|
502 |
goto fail;
|
503 |
} |
504 |
if (write_sync(csock, (char*)name, strlen(name)) != strlen(name)) { |
505 |
LOG("write failed (name)");
|
506 |
goto fail;
|
507 |
} |
508 |
} else {
|
509 |
TRACE("Checking magic (cli_magic)");
|
510 |
|
511 |
if (magic != NBD_CLIENT_MAGIC) {
|
512 |
LOG("Bad magic received");
|
513 |
goto fail;
|
514 |
} |
515 |
} |
516 |
|
517 |
if (read_sync(csock, &s, sizeof(s)) != sizeof(s)) { |
518 |
LOG("read failed");
|
519 |
goto fail;
|
520 |
} |
521 |
*size = be64_to_cpu(s); |
522 |
*blocksize = 1024;
|
523 |
TRACE("Size is %" PRIu64, *size);
|
524 |
|
525 |
if (!name) {
|
526 |
if (read_sync(csock, flags, sizeof(*flags)) != sizeof(*flags)) { |
527 |
LOG("read failed (flags)");
|
528 |
goto fail;
|
529 |
} |
530 |
*flags = be32_to_cpup(flags); |
531 |
} else {
|
532 |
if (read_sync(csock, &tmp, sizeof(tmp)) != sizeof(tmp)) { |
533 |
LOG("read failed (tmp)");
|
534 |
goto fail;
|
535 |
} |
536 |
*flags |= be32_to_cpu(tmp); |
537 |
} |
538 |
if (read_sync(csock, &buf, 124) != 124) { |
539 |
LOG("read failed (buf)");
|
540 |
goto fail;
|
541 |
} |
542 |
rc = 0;
|
543 |
|
544 |
fail:
|
545 |
socket_set_nonblock(csock); |
546 |
return rc;
|
547 |
} |
548 |
|
549 |
#ifdef __linux__
|
550 |
int nbd_init(int fd, int csock, uint32_t flags, off_t size, size_t blocksize) |
551 |
{ |
552 |
TRACE("Setting NBD socket");
|
553 |
|
554 |
if (ioctl(fd, NBD_SET_SOCK, csock) < 0) { |
555 |
int serrno = errno;
|
556 |
LOG("Failed to set NBD socket");
|
557 |
return -serrno;
|
558 |
} |
559 |
|
560 |
TRACE("Setting block size to %lu", (unsigned long)blocksize); |
561 |
|
562 |
if (ioctl(fd, NBD_SET_BLKSIZE, blocksize) < 0) { |
563 |
int serrno = errno;
|
564 |
LOG("Failed setting NBD block size");
|
565 |
return -serrno;
|
566 |
} |
567 |
|
568 |
TRACE("Setting size to %zd block(s)", (size_t)(size / blocksize));
|
569 |
|
570 |
if (ioctl(fd, NBD_SET_SIZE_BLOCKS, size / blocksize) < 0) { |
571 |
int serrno = errno;
|
572 |
LOG("Failed setting size (in blocks)");
|
573 |
return -serrno;
|
574 |
} |
575 |
|
576 |
if (flags & NBD_FLAG_READ_ONLY) {
|
577 |
int read_only = 1; |
578 |
TRACE("Setting readonly attribute");
|
579 |
|
580 |
if (ioctl(fd, BLKROSET, (unsigned long) &read_only) < 0) { |
581 |
int serrno = errno;
|
582 |
LOG("Failed setting read-only attribute");
|
583 |
return -serrno;
|
584 |
} |
585 |
} |
586 |
|
587 |
if (ioctl(fd, NBD_SET_FLAGS, flags) < 0 |
588 |
&& errno != ENOTTY) { |
589 |
int serrno = errno;
|
590 |
LOG("Failed setting flags");
|
591 |
return -serrno;
|
592 |
} |
593 |
|
594 |
TRACE("Negotiation ended");
|
595 |
|
596 |
return 0; |
597 |
} |
598 |
|
599 |
int nbd_disconnect(int fd) |
600 |
{ |
601 |
ioctl(fd, NBD_CLEAR_QUE); |
602 |
ioctl(fd, NBD_DISCONNECT); |
603 |
ioctl(fd, NBD_CLEAR_SOCK); |
604 |
return 0; |
605 |
} |
606 |
|
607 |
int nbd_client(int fd) |
608 |
{ |
609 |
int ret;
|
610 |
int serrno;
|
611 |
|
612 |
TRACE("Doing NBD loop");
|
613 |
|
614 |
ret = ioctl(fd, NBD_DO_IT); |
615 |
if (ret < 0 && errno == EPIPE) { |
616 |
/* NBD_DO_IT normally returns EPIPE when someone has disconnected
|
617 |
* the socket via NBD_DISCONNECT. We do not want to return 1 in
|
618 |
* that case.
|
619 |
*/
|
620 |
ret = 0;
|
621 |
} |
622 |
serrno = errno; |
623 |
|
624 |
TRACE("NBD loop returned %d: %s", ret, strerror(serrno));
|
625 |
|
626 |
TRACE("Clearing NBD queue");
|
627 |
ioctl(fd, NBD_CLEAR_QUE); |
628 |
|
629 |
TRACE("Clearing NBD socket");
|
630 |
ioctl(fd, NBD_CLEAR_SOCK); |
631 |
|
632 |
errno = serrno; |
633 |
return ret;
|
634 |
} |
635 |
#else
|
636 |
int nbd_init(int fd, int csock, uint32_t flags, off_t size, size_t blocksize) |
637 |
{ |
638 |
return -ENOTSUP;
|
639 |
} |
640 |
|
641 |
int nbd_disconnect(int fd) |
642 |
{ |
643 |
return -ENOTSUP;
|
644 |
} |
645 |
|
646 |
int nbd_client(int fd) |
647 |
{ |
648 |
return -ENOTSUP;
|
649 |
} |
650 |
#endif
|
651 |
|
652 |
ssize_t nbd_send_request(int csock, struct nbd_request *request) |
653 |
{ |
654 |
uint8_t buf[NBD_REQUEST_SIZE]; |
655 |
ssize_t ret; |
656 |
|
657 |
cpu_to_be32w((uint32_t*)buf, NBD_REQUEST_MAGIC); |
658 |
cpu_to_be32w((uint32_t*)(buf + 4), request->type);
|
659 |
cpu_to_be64w((uint64_t*)(buf + 8), request->handle);
|
660 |
cpu_to_be64w((uint64_t*)(buf + 16), request->from);
|
661 |
cpu_to_be32w((uint32_t*)(buf + 24), request->len);
|
662 |
|
663 |
TRACE("Sending request to client: "
|
664 |
"{ .from = %" PRIu64", .len = %u, .handle = %" PRIu64", .type=%i}", |
665 |
request->from, request->len, request->handle, request->type); |
666 |
|
667 |
ret = write_sync(csock, buf, sizeof(buf));
|
668 |
if (ret < 0) { |
669 |
return ret;
|
670 |
} |
671 |
|
672 |
if (ret != sizeof(buf)) { |
673 |
LOG("writing to socket failed");
|
674 |
return -EINVAL;
|
675 |
} |
676 |
return 0; |
677 |
} |
678 |
|
679 |
static ssize_t nbd_receive_request(int csock, struct nbd_request *request) |
680 |
{ |
681 |
uint8_t buf[NBD_REQUEST_SIZE]; |
682 |
uint32_t magic; |
683 |
ssize_t ret; |
684 |
|
685 |
ret = read_sync(csock, buf, sizeof(buf));
|
686 |
if (ret < 0) { |
687 |
return ret;
|
688 |
} |
689 |
|
690 |
if (ret != sizeof(buf)) { |
691 |
LOG("read failed");
|
692 |
return -EINVAL;
|
693 |
} |
694 |
|
695 |
/* Request
|
696 |
[ 0 .. 3] magic (NBD_REQUEST_MAGIC)
|
697 |
[ 4 .. 7] type (0 == READ, 1 == WRITE)
|
698 |
[ 8 .. 15] handle
|
699 |
[16 .. 23] from
|
700 |
[24 .. 27] len
|
701 |
*/
|
702 |
|
703 |
magic = be32_to_cpup((uint32_t*)buf); |
704 |
request->type = be32_to_cpup((uint32_t*)(buf + 4));
|
705 |
request->handle = be64_to_cpup((uint64_t*)(buf + 8));
|
706 |
request->from = be64_to_cpup((uint64_t*)(buf + 16));
|
707 |
request->len = be32_to_cpup((uint32_t*)(buf + 24));
|
708 |
|
709 |
TRACE("Got request: "
|
710 |
"{ magic = 0x%x, .type = %d, from = %" PRIu64" , len = %u }", |
711 |
magic, request->type, request->from, request->len); |
712 |
|
713 |
if (magic != NBD_REQUEST_MAGIC) {
|
714 |
LOG("invalid magic (got 0x%x)", magic);
|
715 |
return -EINVAL;
|
716 |
} |
717 |
return 0; |
718 |
} |
719 |
|
720 |
ssize_t nbd_receive_reply(int csock, struct nbd_reply *reply) |
721 |
{ |
722 |
uint8_t buf[NBD_REPLY_SIZE]; |
723 |
uint32_t magic; |
724 |
ssize_t ret; |
725 |
|
726 |
ret = read_sync(csock, buf, sizeof(buf));
|
727 |
if (ret < 0) { |
728 |
return ret;
|
729 |
} |
730 |
|
731 |
if (ret != sizeof(buf)) { |
732 |
LOG("read failed");
|
733 |
return -EINVAL;
|
734 |
} |
735 |
|
736 |
/* Reply
|
737 |
[ 0 .. 3] magic (NBD_REPLY_MAGIC)
|
738 |
[ 4 .. 7] error (0 == no error)
|
739 |
[ 7 .. 15] handle
|
740 |
*/
|
741 |
|
742 |
magic = be32_to_cpup((uint32_t*)buf); |
743 |
reply->error = be32_to_cpup((uint32_t*)(buf + 4));
|
744 |
reply->handle = be64_to_cpup((uint64_t*)(buf + 8));
|
745 |
|
746 |
TRACE("Got reply: "
|
747 |
"{ magic = 0x%x, .error = %d, handle = %" PRIu64" }", |
748 |
magic, reply->error, reply->handle); |
749 |
|
750 |
if (magic != NBD_REPLY_MAGIC) {
|
751 |
LOG("invalid magic (got 0x%x)", magic);
|
752 |
return -EINVAL;
|
753 |
} |
754 |
return 0; |
755 |
} |
756 |
|
757 |
static ssize_t nbd_send_reply(int csock, struct nbd_reply *reply) |
758 |
{ |
759 |
uint8_t buf[NBD_REPLY_SIZE]; |
760 |
ssize_t ret; |
761 |
|
762 |
/* Reply
|
763 |
[ 0 .. 3] magic (NBD_REPLY_MAGIC)
|
764 |
[ 4 .. 7] error (0 == no error)
|
765 |
[ 7 .. 15] handle
|
766 |
*/
|
767 |
cpu_to_be32w((uint32_t*)buf, NBD_REPLY_MAGIC); |
768 |
cpu_to_be32w((uint32_t*)(buf + 4), reply->error);
|
769 |
cpu_to_be64w((uint64_t*)(buf + 8), reply->handle);
|
770 |
|
771 |
TRACE("Sending response to client");
|
772 |
|
773 |
ret = write_sync(csock, buf, sizeof(buf));
|
774 |
if (ret < 0) { |
775 |
return ret;
|
776 |
} |
777 |
|
778 |
if (ret != sizeof(buf)) { |
779 |
LOG("writing to socket failed");
|
780 |
return -EINVAL;
|
781 |
} |
782 |
return 0; |
783 |
} |
784 |
|
785 |
#define MAX_NBD_REQUESTS 16 |
786 |
|
787 |
void nbd_client_get(NBDClient *client)
|
788 |
{ |
789 |
client->refcount++; |
790 |
} |
791 |
|
792 |
void nbd_client_put(NBDClient *client)
|
793 |
{ |
794 |
if (--client->refcount == 0) { |
795 |
/* The last reference should be dropped by client->close,
|
796 |
* which is called by nbd_client_close.
|
797 |
*/
|
798 |
assert(client->closing); |
799 |
|
800 |
qemu_set_fd_handler2(client->sock, NULL, NULL, NULL, NULL); |
801 |
close(client->sock); |
802 |
client->sock = -1;
|
803 |
if (client->exp) {
|
804 |
QTAILQ_REMOVE(&client->exp->clients, client, next); |
805 |
nbd_export_put(client->exp); |
806 |
} |
807 |
g_free(client); |
808 |
} |
809 |
} |
810 |
|
811 |
void nbd_client_close(NBDClient *client)
|
812 |
{ |
813 |
if (client->closing) {
|
814 |
return;
|
815 |
} |
816 |
|
817 |
client->closing = true;
|
818 |
|
819 |
/* Force requests to finish. They will drop their own references,
|
820 |
* then we'll close the socket and free the NBDClient.
|
821 |
*/
|
822 |
shutdown(client->sock, 2);
|
823 |
|
824 |
/* Also tell the client, so that they release their reference. */
|
825 |
if (client->close) {
|
826 |
client->close(client); |
827 |
} |
828 |
} |
829 |
|
830 |
static NBDRequest *nbd_request_get(NBDClient *client)
|
831 |
{ |
832 |
NBDRequest *req; |
833 |
NBDExport *exp = client->exp; |
834 |
|
835 |
assert(client->nb_requests <= MAX_NBD_REQUESTS - 1);
|
836 |
client->nb_requests++; |
837 |
|
838 |
if (QSIMPLEQ_EMPTY(&exp->requests)) {
|
839 |
req = g_malloc0(sizeof(NBDRequest));
|
840 |
req->data = qemu_blockalign(exp->bs, NBD_BUFFER_SIZE); |
841 |
} else {
|
842 |
req = QSIMPLEQ_FIRST(&exp->requests); |
843 |
QSIMPLEQ_REMOVE_HEAD(&exp->requests, entry); |
844 |
} |
845 |
nbd_client_get(client); |
846 |
req->client = client; |
847 |
return req;
|
848 |
} |
849 |
|
850 |
static void nbd_request_put(NBDRequest *req) |
851 |
{ |
852 |
NBDClient *client = req->client; |
853 |
QSIMPLEQ_INSERT_HEAD(&client->exp->requests, req, entry); |
854 |
if (client->nb_requests-- == MAX_NBD_REQUESTS) {
|
855 |
qemu_notify_event(); |
856 |
} |
857 |
nbd_client_put(client); |
858 |
} |
859 |
|
860 |
NBDExport *nbd_export_new(BlockDriverState *bs, off_t dev_offset, |
861 |
off_t size, uint32_t nbdflags, |
862 |
void (*close)(NBDExport *))
|
863 |
{ |
864 |
NBDExport *exp = g_malloc0(sizeof(NBDExport));
|
865 |
QSIMPLEQ_INIT(&exp->requests); |
866 |
exp->refcount = 1;
|
867 |
QTAILQ_INIT(&exp->clients); |
868 |
exp->bs = bs; |
869 |
exp->dev_offset = dev_offset; |
870 |
exp->nbdflags = nbdflags; |
871 |
exp->size = size == -1 ? bdrv_getlength(bs) : size;
|
872 |
exp->close = close; |
873 |
return exp;
|
874 |
} |
875 |
|
876 |
NBDExport *nbd_export_find(const char *name) |
877 |
{ |
878 |
NBDExport *exp; |
879 |
QTAILQ_FOREACH(exp, &exports, next) { |
880 |
if (strcmp(name, exp->name) == 0) { |
881 |
return exp;
|
882 |
} |
883 |
} |
884 |
|
885 |
return NULL; |
886 |
} |
887 |
|
888 |
void nbd_export_set_name(NBDExport *exp, const char *name) |
889 |
{ |
890 |
if (exp->name == name) {
|
891 |
return;
|
892 |
} |
893 |
|
894 |
nbd_export_get(exp); |
895 |
if (exp->name != NULL) { |
896 |
g_free(exp->name); |
897 |
exp->name = NULL;
|
898 |
QTAILQ_REMOVE(&exports, exp, next); |
899 |
nbd_export_put(exp); |
900 |
} |
901 |
if (name != NULL) { |
902 |
nbd_export_get(exp); |
903 |
exp->name = g_strdup(name); |
904 |
QTAILQ_INSERT_TAIL(&exports, exp, next); |
905 |
} |
906 |
nbd_export_put(exp); |
907 |
} |
908 |
|
909 |
void nbd_export_close(NBDExport *exp)
|
910 |
{ |
911 |
NBDClient *client, *next; |
912 |
|
913 |
nbd_export_get(exp); |
914 |
QTAILQ_FOREACH_SAFE(client, &exp->clients, next, next) { |
915 |
nbd_client_close(client); |
916 |
} |
917 |
nbd_export_set_name(exp, NULL);
|
918 |
nbd_export_put(exp); |
919 |
} |
920 |
|
921 |
void nbd_export_get(NBDExport *exp)
|
922 |
{ |
923 |
assert(exp->refcount > 0);
|
924 |
exp->refcount++; |
925 |
} |
926 |
|
927 |
void nbd_export_put(NBDExport *exp)
|
928 |
{ |
929 |
assert(exp->refcount > 0);
|
930 |
if (exp->refcount == 1) { |
931 |
nbd_export_close(exp); |
932 |
} |
933 |
|
934 |
if (--exp->refcount == 0) { |
935 |
assert(exp->name == NULL);
|
936 |
|
937 |
if (exp->close) {
|
938 |
exp->close(exp); |
939 |
} |
940 |
|
941 |
while (!QSIMPLEQ_EMPTY(&exp->requests)) {
|
942 |
NBDRequest *first = QSIMPLEQ_FIRST(&exp->requests); |
943 |
QSIMPLEQ_REMOVE_HEAD(&exp->requests, entry); |
944 |
qemu_vfree(first->data); |
945 |
g_free(first); |
946 |
} |
947 |
|
948 |
g_free(exp); |
949 |
} |
950 |
} |
951 |
|
952 |
BlockDriverState *nbd_export_get_blockdev(NBDExport *exp) |
953 |
{ |
954 |
return exp->bs;
|
955 |
} |
956 |
|
957 |
void nbd_export_close_all(void) |
958 |
{ |
959 |
NBDExport *exp, *next; |
960 |
|
961 |
QTAILQ_FOREACH_SAFE(exp, &exports, next, next) { |
962 |
nbd_export_close(exp); |
963 |
} |
964 |
} |
965 |
|
966 |
static int nbd_can_read(void *opaque); |
967 |
static void nbd_read(void *opaque); |
968 |
static void nbd_restart_write(void *opaque); |
969 |
|
970 |
static ssize_t nbd_co_send_reply(NBDRequest *req, struct nbd_reply *reply, |
971 |
int len)
|
972 |
{ |
973 |
NBDClient *client = req->client; |
974 |
int csock = client->sock;
|
975 |
ssize_t rc, ret; |
976 |
|
977 |
qemu_co_mutex_lock(&client->send_lock); |
978 |
qemu_set_fd_handler2(csock, nbd_can_read, nbd_read, |
979 |
nbd_restart_write, client); |
980 |
client->send_coroutine = qemu_coroutine_self(); |
981 |
|
982 |
if (!len) {
|
983 |
rc = nbd_send_reply(csock, reply); |
984 |
} else {
|
985 |
socket_set_cork(csock, 1);
|
986 |
rc = nbd_send_reply(csock, reply); |
987 |
if (rc >= 0) { |
988 |
ret = qemu_co_send(csock, req->data, len); |
989 |
if (ret != len) {
|
990 |
rc = -EIO; |
991 |
} |
992 |
} |
993 |
socket_set_cork(csock, 0);
|
994 |
} |
995 |
|
996 |
client->send_coroutine = NULL;
|
997 |
qemu_set_fd_handler2(csock, nbd_can_read, nbd_read, NULL, client);
|
998 |
qemu_co_mutex_unlock(&client->send_lock); |
999 |
return rc;
|
1000 |
} |
1001 |
|
1002 |
static ssize_t nbd_co_receive_request(NBDRequest *req, struct nbd_request *request) |
1003 |
{ |
1004 |
NBDClient *client = req->client; |
1005 |
int csock = client->sock;
|
1006 |
ssize_t rc; |
1007 |
|
1008 |
client->recv_coroutine = qemu_coroutine_self(); |
1009 |
rc = nbd_receive_request(csock, request); |
1010 |
if (rc < 0) { |
1011 |
if (rc != -EAGAIN) {
|
1012 |
rc = -EIO; |
1013 |
} |
1014 |
goto out;
|
1015 |
} |
1016 |
|
1017 |
if (request->len > NBD_BUFFER_SIZE) {
|
1018 |
LOG("len (%u) is larger than max len (%u)",
|
1019 |
request->len, NBD_BUFFER_SIZE); |
1020 |
rc = -EINVAL; |
1021 |
goto out;
|
1022 |
} |
1023 |
|
1024 |
if ((request->from + request->len) < request->from) {
|
1025 |
LOG("integer overflow detected! "
|
1026 |
"you're probably being attacked");
|
1027 |
rc = -EINVAL; |
1028 |
goto out;
|
1029 |
} |
1030 |
|
1031 |
TRACE("Decoding type");
|
1032 |
|
1033 |
if ((request->type & NBD_CMD_MASK_COMMAND) == NBD_CMD_WRITE) {
|
1034 |
TRACE("Reading %u byte(s)", request->len);
|
1035 |
|
1036 |
if (qemu_co_recv(csock, req->data, request->len) != request->len) {
|
1037 |
LOG("reading from socket failed");
|
1038 |
rc = -EIO; |
1039 |
goto out;
|
1040 |
} |
1041 |
} |
1042 |
rc = 0;
|
1043 |
|
1044 |
out:
|
1045 |
client->recv_coroutine = NULL;
|
1046 |
return rc;
|
1047 |
} |
1048 |
|
1049 |
static void nbd_trip(void *opaque) |
1050 |
{ |
1051 |
NBDClient *client = opaque; |
1052 |
NBDExport *exp = client->exp; |
1053 |
NBDRequest *req; |
1054 |
struct nbd_request request;
|
1055 |
struct nbd_reply reply;
|
1056 |
ssize_t ret; |
1057 |
|
1058 |
TRACE("Reading request.");
|
1059 |
if (client->closing) {
|
1060 |
return;
|
1061 |
} |
1062 |
|
1063 |
req = nbd_request_get(client); |
1064 |
ret = nbd_co_receive_request(req, &request); |
1065 |
if (ret == -EAGAIN) {
|
1066 |
goto done;
|
1067 |
} |
1068 |
if (ret == -EIO) {
|
1069 |
goto out;
|
1070 |
} |
1071 |
|
1072 |
reply.handle = request.handle; |
1073 |
reply.error = 0;
|
1074 |
|
1075 |
if (ret < 0) { |
1076 |
reply.error = -ret; |
1077 |
goto error_reply;
|
1078 |
} |
1079 |
|
1080 |
if ((request.from + request.len) > exp->size) {
|
1081 |
LOG("From: %" PRIu64 ", Len: %u, Size: %" PRIu64 |
1082 |
", Offset: %" PRIu64 "\n", |
1083 |
request.from, request.len, |
1084 |
(uint64_t)exp->size, (uint64_t)exp->dev_offset); |
1085 |
LOG("requested operation past EOF--bad client?");
|
1086 |
goto invalid_request;
|
1087 |
} |
1088 |
|
1089 |
switch (request.type & NBD_CMD_MASK_COMMAND) {
|
1090 |
case NBD_CMD_READ:
|
1091 |
TRACE("Request type is READ");
|
1092 |
|
1093 |
if (request.type & NBD_CMD_FLAG_FUA) {
|
1094 |
ret = bdrv_co_flush(exp->bs); |
1095 |
if (ret < 0) { |
1096 |
LOG("flush failed");
|
1097 |
reply.error = -ret; |
1098 |
goto error_reply;
|
1099 |
} |
1100 |
} |
1101 |
|
1102 |
ret = bdrv_read(exp->bs, (request.from + exp->dev_offset) / 512,
|
1103 |
req->data, request.len / 512);
|
1104 |
if (ret < 0) { |
1105 |
LOG("reading from file failed");
|
1106 |
reply.error = -ret; |
1107 |
goto error_reply;
|
1108 |
} |
1109 |
|
1110 |
TRACE("Read %u byte(s)", request.len);
|
1111 |
if (nbd_co_send_reply(req, &reply, request.len) < 0) |
1112 |
goto out;
|
1113 |
break;
|
1114 |
case NBD_CMD_WRITE:
|
1115 |
TRACE("Request type is WRITE");
|
1116 |
|
1117 |
if (exp->nbdflags & NBD_FLAG_READ_ONLY) {
|
1118 |
TRACE("Server is read-only, return error");
|
1119 |
reply.error = EROFS; |
1120 |
goto error_reply;
|
1121 |
} |
1122 |
|
1123 |
TRACE("Writing to device");
|
1124 |
|
1125 |
ret = bdrv_write(exp->bs, (request.from + exp->dev_offset) / 512,
|
1126 |
req->data, request.len / 512);
|
1127 |
if (ret < 0) { |
1128 |
LOG("writing to file failed");
|
1129 |
reply.error = -ret; |
1130 |
goto error_reply;
|
1131 |
} |
1132 |
|
1133 |
if (request.type & NBD_CMD_FLAG_FUA) {
|
1134 |
ret = bdrv_co_flush(exp->bs); |
1135 |
if (ret < 0) { |
1136 |
LOG("flush failed");
|
1137 |
reply.error = -ret; |
1138 |
goto error_reply;
|
1139 |
} |
1140 |
} |
1141 |
|
1142 |
if (nbd_co_send_reply(req, &reply, 0) < 0) { |
1143 |
goto out;
|
1144 |
} |
1145 |
break;
|
1146 |
case NBD_CMD_DISC:
|
1147 |
TRACE("Request type is DISCONNECT");
|
1148 |
errno = 0;
|
1149 |
goto out;
|
1150 |
case NBD_CMD_FLUSH:
|
1151 |
TRACE("Request type is FLUSH");
|
1152 |
|
1153 |
ret = bdrv_co_flush(exp->bs); |
1154 |
if (ret < 0) { |
1155 |
LOG("flush failed");
|
1156 |
reply.error = -ret; |
1157 |
} |
1158 |
if (nbd_co_send_reply(req, &reply, 0) < 0) { |
1159 |
goto out;
|
1160 |
} |
1161 |
break;
|
1162 |
case NBD_CMD_TRIM:
|
1163 |
TRACE("Request type is TRIM");
|
1164 |
ret = bdrv_co_discard(exp->bs, (request.from + exp->dev_offset) / 512,
|
1165 |
request.len / 512);
|
1166 |
if (ret < 0) { |
1167 |
LOG("discard failed");
|
1168 |
reply.error = -ret; |
1169 |
} |
1170 |
if (nbd_co_send_reply(req, &reply, 0) < 0) { |
1171 |
goto out;
|
1172 |
} |
1173 |
break;
|
1174 |
default:
|
1175 |
LOG("invalid request type (%u) received", request.type);
|
1176 |
invalid_request:
|
1177 |
reply.error = -EINVAL; |
1178 |
error_reply:
|
1179 |
if (nbd_co_send_reply(req, &reply, 0) < 0) { |
1180 |
goto out;
|
1181 |
} |
1182 |
break;
|
1183 |
} |
1184 |
|
1185 |
TRACE("Request/Reply complete");
|
1186 |
|
1187 |
done:
|
1188 |
nbd_request_put(req); |
1189 |
return;
|
1190 |
|
1191 |
out:
|
1192 |
nbd_request_put(req); |
1193 |
nbd_client_close(client); |
1194 |
} |
1195 |
|
1196 |
static int nbd_can_read(void *opaque) |
1197 |
{ |
1198 |
NBDClient *client = opaque; |
1199 |
|
1200 |
return client->recv_coroutine || client->nb_requests < MAX_NBD_REQUESTS;
|
1201 |
} |
1202 |
|
1203 |
static void nbd_read(void *opaque) |
1204 |
{ |
1205 |
NBDClient *client = opaque; |
1206 |
|
1207 |
if (client->recv_coroutine) {
|
1208 |
qemu_coroutine_enter(client->recv_coroutine, NULL);
|
1209 |
} else {
|
1210 |
qemu_coroutine_enter(qemu_coroutine_create(nbd_trip), client); |
1211 |
} |
1212 |
} |
1213 |
|
1214 |
static void nbd_restart_write(void *opaque) |
1215 |
{ |
1216 |
NBDClient *client = opaque; |
1217 |
|
1218 |
qemu_coroutine_enter(client->send_coroutine, NULL);
|
1219 |
} |
1220 |
|
1221 |
NBDClient *nbd_client_new(NBDExport *exp, int csock,
|
1222 |
void (*close)(NBDClient *))
|
1223 |
{ |
1224 |
NBDClient *client; |
1225 |
client = g_malloc0(sizeof(NBDClient));
|
1226 |
client->refcount = 1;
|
1227 |
client->exp = exp; |
1228 |
client->sock = csock; |
1229 |
if (nbd_send_negotiate(client) < 0) { |
1230 |
g_free(client); |
1231 |
return NULL; |
1232 |
} |
1233 |
client->close = close; |
1234 |
qemu_co_mutex_init(&client->send_lock); |
1235 |
qemu_set_fd_handler2(csock, nbd_can_read, nbd_read, NULL, client);
|
1236 |
|
1237 |
if (exp) {
|
1238 |
QTAILQ_INSERT_TAIL(&exp->clients, client, next); |
1239 |
nbd_export_get(exp); |
1240 |
} |
1241 |
return client;
|
1242 |
} |