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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 <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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|
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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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#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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|
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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_OPT_EXPORT_NAME (1 << 0) |
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/* That's all folks */
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#define read_sync(fd, buffer, size) nbd_wr_sync(fd, buffer, size, true) |
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#define write_sync(fd, buffer, size) nbd_wr_sync(fd, buffer, size, false) |
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size_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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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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} |
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if (len == -1) |
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errno = socket_error(); |
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/* recoverable error */
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if (len == -1 && (errno == EAGAIN || errno == EINTR)) { |
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continue;
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} |
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/* eof */
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if (len == 0) { |
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break;
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} |
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/* unrecoverable error */
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if (len == -1) { |
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return 0; |
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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 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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} |
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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, SOCK_STREAM);
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} |
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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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} |
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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; |
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return inet_listen(address_and_port, ostr, olen, SOCK_STREAM, 0); |
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} |
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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; |
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return unix_listen(path, ostr, olen);
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} |
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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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} |
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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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int nbd_negotiate(int csock, off_t size, uint32_t flags) |
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{
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char buf[8 + 8 + 8 + 128]; |
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|
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/* Negotiate
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[ 0 .. 7] passwd ("NBDMAGIC")
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[ 8 .. 15] magic (0x00420281861253)
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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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TRACE("Beginning negotiation.");
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memcpy(buf, "NBDMAGIC", 8); |
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cpu_to_be64w((uint64_t*)(buf + 8), 0x00420281861253LL); |
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cpu_to_be64w((uint64_t*)(buf + 16), size);
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cpu_to_be32w((uint32_t*)(buf + 24), flags | NBD_FLAG_HAS_FLAGS);
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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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errno = EINVAL; |
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return -1; |
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} |
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TRACE("Negotation succeeded.");
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return 0; |
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} |
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int nbd_receive_negotiate(int csock, const char *name, uint32_t *flags, |
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off_t *size, size_t *blocksize) |
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{
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char buf[256]; |
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uint64_t magic, s; |
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uint16_t tmp; |
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TRACE("Receiving negotation.");
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if (read_sync(csock, buf, 8) != 8) { |
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LOG("read failed");
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errno = EINVAL; |
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return -1; |
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} |
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buf[8] = '\0'; |
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if (strlen(buf) == 0) { |
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LOG("server connection closed");
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errno = EINVAL; |
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return -1; |
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} |
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TRACE("Magic is %c%c%c%c%c%c%c%c",
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qemu_isprint(buf[0]) ? buf[0] : '.', |
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qemu_isprint(buf[1]) ? buf[1] : '.', |
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qemu_isprint(buf[2]) ? buf[2] : '.', |
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qemu_isprint(buf[3]) ? buf[3] : '.', |
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qemu_isprint(buf[4]) ? buf[4] : '.', |
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qemu_isprint(buf[5]) ? buf[5] : '.', |
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qemu_isprint(buf[6]) ? buf[6] : '.', |
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qemu_isprint(buf[7]) ? buf[7] : '.'); |
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if (memcmp(buf, "NBDMAGIC", 8) != 0) { |
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LOG("Invalid magic received");
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errno = EINVAL; |
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return -1; |
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} |
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if (read_sync(csock, &magic, sizeof(magic)) != sizeof(magic)) { |
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LOG("read failed");
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errno = EINVAL; |
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return -1; |
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} |
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magic = be64_to_cpu(magic); |
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TRACE("Magic is 0x%" PRIx64, magic);
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if (name) {
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uint32_t reserved = 0;
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uint32_t opt; |
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uint32_t namesize; |
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TRACE("Checking magic (opts_magic)");
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if (magic != 0x49484156454F5054LL) { |
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LOG("Bad magic received");
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errno = EINVAL; |
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return -1; |
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} |
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if (read_sync(csock, &tmp, sizeof(tmp)) != sizeof(tmp)) { |
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LOG("flags read failed");
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errno = EINVAL; |
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return -1; |
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} |
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*flags = be16_to_cpu(tmp) << 16;
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/* reserved for future use */
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if (write_sync(csock, &reserved, sizeof(reserved)) != |
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sizeof(reserved)) {
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LOG("write failed (reserved)");
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errno = EINVAL; |
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return -1; |
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} |
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/* write the export name */
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magic = cpu_to_be64(magic); |
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if (write_sync(csock, &magic, sizeof(magic)) != sizeof(magic)) { |
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LOG("write failed (magic)");
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errno = EINVAL; |
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return -1; |
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} |
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opt = cpu_to_be32(NBD_OPT_EXPORT_NAME); |
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if (write_sync(csock, &opt, sizeof(opt)) != sizeof(opt)) { |
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LOG("write failed (opt)");
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errno = EINVAL; |
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return -1; |
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} |
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namesize = cpu_to_be32(strlen(name)); |
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if (write_sync(csock, &namesize, sizeof(namesize)) != |
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sizeof(namesize)) {
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LOG("write failed (namesize)");
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errno = EINVAL; |
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return -1; |
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} |
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if (write_sync(csock, (char*)name, strlen(name)) != strlen(name)) { |
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LOG("write failed (name)");
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errno = EINVAL; |
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return -1; |
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} |
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} else {
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TRACE("Checking magic (cli_magic)");
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if (magic != 0x00420281861253LL) { |
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LOG("Bad magic received");
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errno = EINVAL; |
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return -1; |
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} |
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} |
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|
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if (read_sync(csock, &s, sizeof(s)) != sizeof(s)) { |
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LOG("read failed");
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errno = EINVAL; |
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return -1; |
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} |
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*size = be64_to_cpu(s); |
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*blocksize = 1024;
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TRACE("Size is %" PRIu64, *size);
|
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|
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if (!name) {
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if (read_sync(csock, flags, sizeof(*flags)) != sizeof(*flags)) { |
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LOG("read failed (flags)");
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errno = EINVAL; |
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return -1; |
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} |
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*flags = be32_to_cpup(flags); |
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} else {
|
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if (read_sync(csock, &tmp, sizeof(tmp)) != sizeof(tmp)) { |
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LOG("read failed (tmp)");
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errno = EINVAL; |
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return -1; |
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} |
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*flags |= be32_to_cpu(tmp); |
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} |
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if (read_sync(csock, &buf, 124) != 124) { |
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LOG("read failed (buf)");
|
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errno = EINVAL; |
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return -1; |
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} |
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return 0; |
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} |
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|
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#ifdef __linux__
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int nbd_init(int fd, int csock, uint32_t flags, off_t size, size_t blocksize) |
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{
|
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TRACE("Setting block size to %lu", (unsigned long)blocksize); |
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|
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if (ioctl(fd, NBD_SET_BLKSIZE, blocksize) == -1) { |
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int serrno = errno;
|
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LOG("Failed setting NBD block size");
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errno = serrno; |
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return -1; |
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} |
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|
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TRACE("Setting size to %zd block(s)", (size_t)(size / blocksize));
|
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|
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if (ioctl(fd, NBD_SET_SIZE_BLOCKS, size / blocksize) == -1) { |
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int serrno = errno;
|
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LOG("Failed setting size (in blocks)");
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errno = serrno; |
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return -1; |
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} |
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|
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if (flags & NBD_FLAG_READ_ONLY) {
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int read_only = 1; |
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TRACE("Setting readonly attribute");
|
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|
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if (ioctl(fd, BLKROSET, (unsigned long) &read_only) < 0) { |
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int serrno = errno;
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LOG("Failed setting read-only attribute");
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errno = serrno; |
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return -1; |
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} |
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} |
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|
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TRACE("Clearing NBD socket");
|
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|
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if (ioctl(fd, NBD_CLEAR_SOCK) == -1) { |
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int serrno = errno;
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LOG("Failed clearing NBD socket");
|
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errno = serrno; |
| 385 |
return -1; |
| 386 |
} |
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|
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TRACE("Setting NBD socket");
|
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|
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if (ioctl(fd, NBD_SET_SOCK, csock) == -1) { |
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int serrno = errno;
|
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LOG("Failed to set NBD socket");
|
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errno = serrno; |
| 394 |
return -1; |
| 395 |
} |
| 396 |
|
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TRACE("Negotiation ended");
|
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|
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return 0; |
| 400 |
} |
| 401 |
|
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int nbd_disconnect(int fd) |
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{
|
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ioctl(fd, NBD_CLEAR_QUE); |
| 405 |
ioctl(fd, NBD_DISCONNECT); |
| 406 |
ioctl(fd, NBD_CLEAR_SOCK); |
| 407 |
return 0; |
| 408 |
} |
| 409 |
|
| 410 |
int nbd_client(int fd) |
| 411 |
{
|
| 412 |
int ret;
|
| 413 |
int serrno;
|
| 414 |
|
| 415 |
TRACE("Doing NBD loop");
|
| 416 |
|
| 417 |
ret = ioctl(fd, NBD_DO_IT); |
| 418 |
serrno = errno; |
| 419 |
|
| 420 |
TRACE("NBD loop returned %d: %s", ret, strerror(serrno));
|
| 421 |
|
| 422 |
TRACE("Clearing NBD queue");
|
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ioctl(fd, NBD_CLEAR_QUE); |
| 424 |
|
| 425 |
TRACE("Clearing NBD socket");
|
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ioctl(fd, NBD_CLEAR_SOCK); |
| 427 |
|
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errno = serrno; |
| 429 |
return ret;
|
| 430 |
} |
| 431 |
#else
|
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int nbd_init(int fd, int csock, off_t size, size_t blocksize) |
| 433 |
{
|
| 434 |
errno = ENOTSUP; |
| 435 |
return -1; |
| 436 |
} |
| 437 |
|
| 438 |
int nbd_disconnect(int fd) |
| 439 |
{
|
| 440 |
errno = ENOTSUP; |
| 441 |
return -1; |
| 442 |
} |
| 443 |
|
| 444 |
int nbd_client(int fd) |
| 445 |
{
|
| 446 |
errno = ENOTSUP; |
| 447 |
return -1; |
| 448 |
} |
| 449 |
#endif
|
| 450 |
|
| 451 |
int nbd_send_request(int csock, struct nbd_request *request) |
| 452 |
{
|
| 453 |
uint8_t buf[4 + 4 + 8 + 8 + 4]; |
| 454 |
|
| 455 |
cpu_to_be32w((uint32_t*)buf, NBD_REQUEST_MAGIC); |
| 456 |
cpu_to_be32w((uint32_t*)(buf + 4), request->type);
|
| 457 |
cpu_to_be64w((uint64_t*)(buf + 8), request->handle);
|
| 458 |
cpu_to_be64w((uint64_t*)(buf + 16), request->from);
|
| 459 |
cpu_to_be32w((uint32_t*)(buf + 24), request->len);
|
| 460 |
|
| 461 |
TRACE("Sending request to client: "
|
| 462 |
"{ .from = %" PRIu64", .len = %u, .handle = %" PRIu64", .type=%i}", |
| 463 |
request->from, request->len, request->handle, request->type); |
| 464 |
|
| 465 |
if (write_sync(csock, buf, sizeof(buf)) != sizeof(buf)) { |
| 466 |
LOG("writing to socket failed");
|
| 467 |
errno = EINVAL; |
| 468 |
return -1; |
| 469 |
} |
| 470 |
return 0; |
| 471 |
} |
| 472 |
|
| 473 |
static int nbd_receive_request(int csock, struct nbd_request *request) |
| 474 |
{
|
| 475 |
uint8_t buf[4 + 4 + 8 + 8 + 4]; |
| 476 |
uint32_t magic; |
| 477 |
|
| 478 |
if (read_sync(csock, buf, sizeof(buf)) != sizeof(buf)) { |
| 479 |
LOG("read failed");
|
| 480 |
errno = EINVAL; |
| 481 |
return -1; |
| 482 |
} |
| 483 |
|
| 484 |
/* Request
|
| 485 |
[ 0 .. 3] magic (NBD_REQUEST_MAGIC)
|
| 486 |
[ 4 .. 7] type (0 == READ, 1 == WRITE)
|
| 487 |
[ 8 .. 15] handle
|
| 488 |
[16 .. 23] from
|
| 489 |
[24 .. 27] len
|
| 490 |
*/
|
| 491 |
|
| 492 |
magic = be32_to_cpup((uint32_t*)buf); |
| 493 |
request->type = be32_to_cpup((uint32_t*)(buf + 4));
|
| 494 |
request->handle = be64_to_cpup((uint64_t*)(buf + 8));
|
| 495 |
request->from = be64_to_cpup((uint64_t*)(buf + 16));
|
| 496 |
request->len = be32_to_cpup((uint32_t*)(buf + 24));
|
| 497 |
|
| 498 |
TRACE("Got request: "
|
| 499 |
"{ magic = 0x%x, .type = %d, from = %" PRIu64" , len = %u }", |
| 500 |
magic, request->type, request->from, request->len); |
| 501 |
|
| 502 |
if (magic != NBD_REQUEST_MAGIC) {
|
| 503 |
LOG("invalid magic (got 0x%x)", magic);
|
| 504 |
errno = EINVAL; |
| 505 |
return -1; |
| 506 |
} |
| 507 |
return 0; |
| 508 |
} |
| 509 |
|
| 510 |
int nbd_receive_reply(int csock, struct nbd_reply *reply) |
| 511 |
{
|
| 512 |
uint8_t buf[NBD_REPLY_SIZE]; |
| 513 |
uint32_t magic; |
| 514 |
|
| 515 |
memset(buf, 0xAA, sizeof(buf)); |
| 516 |
|
| 517 |
if (read_sync(csock, buf, sizeof(buf)) != sizeof(buf)) { |
| 518 |
LOG("read failed");
|
| 519 |
errno = EINVAL; |
| 520 |
return -1; |
| 521 |
} |
| 522 |
|
| 523 |
/* Reply
|
| 524 |
[ 0 .. 3] magic (NBD_REPLY_MAGIC)
|
| 525 |
[ 4 .. 7] error (0 == no error)
|
| 526 |
[ 7 .. 15] handle
|
| 527 |
*/
|
| 528 |
|
| 529 |
magic = be32_to_cpup((uint32_t*)buf); |
| 530 |
reply->error = be32_to_cpup((uint32_t*)(buf + 4));
|
| 531 |
reply->handle = be64_to_cpup((uint64_t*)(buf + 8));
|
| 532 |
|
| 533 |
TRACE("Got reply: "
|
| 534 |
"{ magic = 0x%x, .error = %d, handle = %" PRIu64" }", |
| 535 |
magic, reply->error, reply->handle); |
| 536 |
|
| 537 |
if (magic != NBD_REPLY_MAGIC) {
|
| 538 |
LOG("invalid magic (got 0x%x)", magic);
|
| 539 |
errno = EINVAL; |
| 540 |
return -1; |
| 541 |
} |
| 542 |
return 0; |
| 543 |
} |
| 544 |
|
| 545 |
static int nbd_send_reply(int csock, struct nbd_reply *reply) |
| 546 |
{
|
| 547 |
uint8_t buf[4 + 4 + 8]; |
| 548 |
|
| 549 |
/* Reply
|
| 550 |
[ 0 .. 3] magic (NBD_REPLY_MAGIC)
|
| 551 |
[ 4 .. 7] error (0 == no error)
|
| 552 |
[ 7 .. 15] handle
|
| 553 |
*/
|
| 554 |
cpu_to_be32w((uint32_t*)buf, NBD_REPLY_MAGIC); |
| 555 |
cpu_to_be32w((uint32_t*)(buf + 4), reply->error);
|
| 556 |
cpu_to_be64w((uint64_t*)(buf + 8), reply->handle);
|
| 557 |
|
| 558 |
TRACE("Sending response to client");
|
| 559 |
|
| 560 |
if (write_sync(csock, buf, sizeof(buf)) != sizeof(buf)) { |
| 561 |
LOG("writing to socket failed");
|
| 562 |
errno = EINVAL; |
| 563 |
return -1; |
| 564 |
} |
| 565 |
return 0; |
| 566 |
} |
| 567 |
|
| 568 |
int nbd_trip(BlockDriverState *bs, int csock, off_t size, uint64_t dev_offset, |
| 569 |
off_t *offset, uint32_t nbdflags, uint8_t *data, int data_size)
|
| 570 |
{
|
| 571 |
struct nbd_request request;
|
| 572 |
struct nbd_reply reply;
|
| 573 |
|
| 574 |
TRACE("Reading request.");
|
| 575 |
|
| 576 |
if (nbd_receive_request(csock, &request) == -1) |
| 577 |
return -1; |
| 578 |
|
| 579 |
if (request.len + NBD_REPLY_SIZE > data_size) {
|
| 580 |
LOG("len (%u) is larger than max len (%u)",
|
| 581 |
request.len + NBD_REPLY_SIZE, data_size); |
| 582 |
errno = EINVAL; |
| 583 |
return -1; |
| 584 |
} |
| 585 |
|
| 586 |
if ((request.from + request.len) < request.from) {
|
| 587 |
LOG("integer overflow detected! "
|
| 588 |
"you're probably being attacked");
|
| 589 |
errno = EINVAL; |
| 590 |
return -1; |
| 591 |
} |
| 592 |
|
| 593 |
if ((request.from + request.len) > size) {
|
| 594 |
LOG("From: %" PRIu64 ", Len: %u, Size: %" PRIu64 |
| 595 |
", Offset: %" PRIu64 "\n", |
| 596 |
request.from, request.len, (uint64_t)size, dev_offset); |
| 597 |
LOG("requested operation past EOF--bad client?");
|
| 598 |
errno = EINVAL; |
| 599 |
return -1; |
| 600 |
} |
| 601 |
|
| 602 |
TRACE("Decoding type");
|
| 603 |
|
| 604 |
reply.handle = request.handle; |
| 605 |
reply.error = 0;
|
| 606 |
|
| 607 |
switch (request.type) {
|
| 608 |
case NBD_CMD_READ:
|
| 609 |
TRACE("Request type is READ");
|
| 610 |
|
| 611 |
if (bdrv_read(bs, (request.from + dev_offset) / 512, |
| 612 |
data + NBD_REPLY_SIZE, |
| 613 |
request.len / 512) == -1) { |
| 614 |
LOG("reading from file failed");
|
| 615 |
errno = EINVAL; |
| 616 |
return -1; |
| 617 |
} |
| 618 |
*offset += request.len; |
| 619 |
|
| 620 |
TRACE("Read %u byte(s)", request.len);
|
| 621 |
|
| 622 |
/* Reply
|
| 623 |
[ 0 .. 3] magic (NBD_REPLY_MAGIC)
|
| 624 |
[ 4 .. 7] error (0 == no error)
|
| 625 |
[ 7 .. 15] handle
|
| 626 |
*/
|
| 627 |
|
| 628 |
cpu_to_be32w((uint32_t*)data, NBD_REPLY_MAGIC); |
| 629 |
cpu_to_be32w((uint32_t*)(data + 4), reply.error);
|
| 630 |
cpu_to_be64w((uint64_t*)(data + 8), reply.handle);
|
| 631 |
|
| 632 |
TRACE("Sending data to client");
|
| 633 |
|
| 634 |
if (write_sync(csock, data,
|
| 635 |
request.len + NBD_REPLY_SIZE) != |
| 636 |
request.len + NBD_REPLY_SIZE) {
|
| 637 |
LOG("writing to socket failed");
|
| 638 |
errno = EINVAL; |
| 639 |
return -1; |
| 640 |
} |
| 641 |
break;
|
| 642 |
case NBD_CMD_WRITE:
|
| 643 |
TRACE("Request type is WRITE");
|
| 644 |
|
| 645 |
TRACE("Reading %u byte(s)", request.len);
|
| 646 |
|
| 647 |
if (read_sync(csock, data, request.len) != request.len) {
|
| 648 |
LOG("reading from socket failed");
|
| 649 |
errno = EINVAL; |
| 650 |
return -1; |
| 651 |
} |
| 652 |
|
| 653 |
if (nbdflags & NBD_FLAG_READ_ONLY) {
|
| 654 |
TRACE("Server is read-only, return error");
|
| 655 |
reply.error = 1;
|
| 656 |
} else {
|
| 657 |
TRACE("Writing to device");
|
| 658 |
|
| 659 |
if (bdrv_write(bs, (request.from + dev_offset) / 512, |
| 660 |
data, request.len / 512) == -1) { |
| 661 |
LOG("writing to file failed");
|
| 662 |
errno = EINVAL; |
| 663 |
return -1; |
| 664 |
} |
| 665 |
|
| 666 |
*offset += request.len; |
| 667 |
} |
| 668 |
|
| 669 |
if (nbd_send_reply(csock, &reply) == -1) |
| 670 |
return -1; |
| 671 |
break;
|
| 672 |
case NBD_CMD_DISC:
|
| 673 |
TRACE("Request type is DISCONNECT");
|
| 674 |
errno = 0;
|
| 675 |
return 1; |
| 676 |
default:
|
| 677 |
LOG("invalid request type (%u) received", request.type);
|
| 678 |
errno = EINVAL; |
| 679 |
return -1; |
| 680 |
} |
| 681 |
|
| 682 |
TRACE("Request/Reply complete");
|
| 683 |
|
| 684 |
return 0; |
| 685 |
} |