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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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//#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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#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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#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_SET_TIMEOUT _IO(0xab, 9) |
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#define NBD_SET_FLAGS _IO(0xab, 10) |
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#define NBD_OPT_EXPORT_NAME (1 << 0) |
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/* 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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/* 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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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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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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#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); |
352 |
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if (ioctl(fd, NBD_SET_BLKSIZE, blocksize) == -1) { |
354 |
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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} |
359 |
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TRACE("Setting size to %zd block(s)", (size_t)(size / blocksize));
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362 |
if (ioctl(fd, NBD_SET_SIZE_BLOCKS, size / blocksize) == -1) { |
363 |
int serrno = errno;
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LOG("Failed setting size (in blocks)");
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errno = serrno; |
366 |
return -1; |
367 |
} |
368 |
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369 |
if (flags & NBD_FLAG_READ_ONLY) {
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370 |
int read_only = 1; |
371 |
TRACE("Setting readonly attribute");
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373 |
if (ioctl(fd, BLKROSET, (unsigned long) &read_only) < 0) { |
374 |
int serrno = errno;
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LOG("Failed setting read-only attribute");
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errno = serrno; |
377 |
return -1; |
378 |
} |
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} |
380 |
|
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if (ioctl(fd, NBD_SET_FLAGS, flags) < 0 |
382 |
&& errno != ENOTTY) { |
383 |
int serrno = errno;
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384 |
LOG("Failed setting flags");
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errno = serrno; |
386 |
return -1; |
387 |
} |
388 |
|
389 |
TRACE("Clearing NBD socket");
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390 |
|
391 |
if (ioctl(fd, NBD_CLEAR_SOCK) == -1) { |
392 |
int serrno = errno;
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393 |
LOG("Failed clearing NBD socket");
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394 |
errno = serrno; |
395 |
return -1; |
396 |
} |
397 |
|
398 |
TRACE("Setting NBD socket");
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399 |
|
400 |
if (ioctl(fd, NBD_SET_SOCK, csock) == -1) { |
401 |
int serrno = errno;
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402 |
LOG("Failed to set NBD socket");
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403 |
errno = serrno; |
404 |
return -1; |
405 |
} |
406 |
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407 |
TRACE("Negotiation ended");
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408 |
|
409 |
return 0; |
410 |
} |
411 |
|
412 |
int nbd_disconnect(int fd) |
413 |
{ |
414 |
ioctl(fd, NBD_CLEAR_QUE); |
415 |
ioctl(fd, NBD_DISCONNECT); |
416 |
ioctl(fd, NBD_CLEAR_SOCK); |
417 |
return 0; |
418 |
} |
419 |
|
420 |
int nbd_client(int fd) |
421 |
{ |
422 |
int ret;
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423 |
int serrno;
|
424 |
|
425 |
TRACE("Doing NBD loop");
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426 |
|
427 |
ret = ioctl(fd, NBD_DO_IT); |
428 |
if (ret == -1 && errno == EPIPE) { |
429 |
/* NBD_DO_IT normally returns EPIPE when someone has disconnected
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430 |
* the socket via NBD_DISCONNECT. We do not want to return 1 in
|
431 |
* that case.
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432 |
*/
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433 |
ret = 0;
|
434 |
} |
435 |
serrno = errno; |
436 |
|
437 |
TRACE("NBD loop returned %d: %s", ret, strerror(serrno));
|
438 |
|
439 |
TRACE("Clearing NBD queue");
|
440 |
ioctl(fd, NBD_CLEAR_QUE); |
441 |
|
442 |
TRACE("Clearing NBD socket");
|
443 |
ioctl(fd, NBD_CLEAR_SOCK); |
444 |
|
445 |
errno = serrno; |
446 |
return ret;
|
447 |
} |
448 |
#else
|
449 |
int nbd_init(int fd, int csock, uint32_t flags, off_t size, size_t blocksize) |
450 |
{ |
451 |
errno = ENOTSUP; |
452 |
return -1; |
453 |
} |
454 |
|
455 |
int nbd_disconnect(int fd) |
456 |
{ |
457 |
errno = ENOTSUP; |
458 |
return -1; |
459 |
} |
460 |
|
461 |
int nbd_client(int fd) |
462 |
{ |
463 |
errno = ENOTSUP; |
464 |
return -1; |
465 |
} |
466 |
#endif
|
467 |
|
468 |
int nbd_send_request(int csock, struct nbd_request *request) |
469 |
{ |
470 |
uint8_t buf[4 + 4 + 8 + 8 + 4]; |
471 |
|
472 |
cpu_to_be32w((uint32_t*)buf, NBD_REQUEST_MAGIC); |
473 |
cpu_to_be32w((uint32_t*)(buf + 4), request->type);
|
474 |
cpu_to_be64w((uint64_t*)(buf + 8), request->handle);
|
475 |
cpu_to_be64w((uint64_t*)(buf + 16), request->from);
|
476 |
cpu_to_be32w((uint32_t*)(buf + 24), request->len);
|
477 |
|
478 |
TRACE("Sending request to client: "
|
479 |
"{ .from = %" PRIu64", .len = %u, .handle = %" PRIu64", .type=%i}", |
480 |
request->from, request->len, request->handle, request->type); |
481 |
|
482 |
if (write_sync(csock, buf, sizeof(buf)) != sizeof(buf)) { |
483 |
LOG("writing to socket failed");
|
484 |
errno = EINVAL; |
485 |
return -1; |
486 |
} |
487 |
return 0; |
488 |
} |
489 |
|
490 |
static int nbd_receive_request(int csock, struct nbd_request *request) |
491 |
{ |
492 |
uint8_t buf[4 + 4 + 8 + 8 + 4]; |
493 |
uint32_t magic; |
494 |
|
495 |
if (read_sync(csock, buf, sizeof(buf)) != sizeof(buf)) { |
496 |
LOG("read failed");
|
497 |
errno = EINVAL; |
498 |
return -1; |
499 |
} |
500 |
|
501 |
/* Request
|
502 |
[ 0 .. 3] magic (NBD_REQUEST_MAGIC)
|
503 |
[ 4 .. 7] type (0 == READ, 1 == WRITE)
|
504 |
[ 8 .. 15] handle
|
505 |
[16 .. 23] from
|
506 |
[24 .. 27] len
|
507 |
*/
|
508 |
|
509 |
magic = be32_to_cpup((uint32_t*)buf); |
510 |
request->type = be32_to_cpup((uint32_t*)(buf + 4));
|
511 |
request->handle = be64_to_cpup((uint64_t*)(buf + 8));
|
512 |
request->from = be64_to_cpup((uint64_t*)(buf + 16));
|
513 |
request->len = be32_to_cpup((uint32_t*)(buf + 24));
|
514 |
|
515 |
TRACE("Got request: "
|
516 |
"{ magic = 0x%x, .type = %d, from = %" PRIu64" , len = %u }", |
517 |
magic, request->type, request->from, request->len); |
518 |
|
519 |
if (magic != NBD_REQUEST_MAGIC) {
|
520 |
LOG("invalid magic (got 0x%x)", magic);
|
521 |
errno = EINVAL; |
522 |
return -1; |
523 |
} |
524 |
return 0; |
525 |
} |
526 |
|
527 |
int nbd_receive_reply(int csock, struct nbd_reply *reply) |
528 |
{ |
529 |
uint8_t buf[NBD_REPLY_SIZE]; |
530 |
uint32_t magic; |
531 |
|
532 |
memset(buf, 0xAA, sizeof(buf)); |
533 |
|
534 |
if (read_sync(csock, buf, sizeof(buf)) != sizeof(buf)) { |
535 |
LOG("read failed");
|
536 |
errno = EINVAL; |
537 |
return -1; |
538 |
} |
539 |
|
540 |
/* Reply
|
541 |
[ 0 .. 3] magic (NBD_REPLY_MAGIC)
|
542 |
[ 4 .. 7] error (0 == no error)
|
543 |
[ 7 .. 15] handle
|
544 |
*/
|
545 |
|
546 |
magic = be32_to_cpup((uint32_t*)buf); |
547 |
reply->error = be32_to_cpup((uint32_t*)(buf + 4));
|
548 |
reply->handle = be64_to_cpup((uint64_t*)(buf + 8));
|
549 |
|
550 |
TRACE("Got reply: "
|
551 |
"{ magic = 0x%x, .error = %d, handle = %" PRIu64" }", |
552 |
magic, reply->error, reply->handle); |
553 |
|
554 |
if (magic != NBD_REPLY_MAGIC) {
|
555 |
LOG("invalid magic (got 0x%x)", magic);
|
556 |
errno = EINVAL; |
557 |
return -1; |
558 |
} |
559 |
return 0; |
560 |
} |
561 |
|
562 |
static int nbd_send_reply(int csock, struct nbd_reply *reply) |
563 |
{ |
564 |
uint8_t buf[4 + 4 + 8]; |
565 |
|
566 |
/* Reply
|
567 |
[ 0 .. 3] magic (NBD_REPLY_MAGIC)
|
568 |
[ 4 .. 7] error (0 == no error)
|
569 |
[ 7 .. 15] handle
|
570 |
*/
|
571 |
cpu_to_be32w((uint32_t*)buf, NBD_REPLY_MAGIC); |
572 |
cpu_to_be32w((uint32_t*)(buf + 4), reply->error);
|
573 |
cpu_to_be64w((uint64_t*)(buf + 8), reply->handle);
|
574 |
|
575 |
TRACE("Sending response to client");
|
576 |
|
577 |
if (write_sync(csock, buf, sizeof(buf)) != sizeof(buf)) { |
578 |
LOG("writing to socket failed");
|
579 |
errno = EINVAL; |
580 |
return -1; |
581 |
} |
582 |
return 0; |
583 |
} |
584 |
|
585 |
int nbd_trip(BlockDriverState *bs, int csock, off_t size, uint64_t dev_offset, |
586 |
off_t *offset, uint32_t nbdflags, uint8_t *data, int data_size)
|
587 |
{ |
588 |
struct nbd_request request;
|
589 |
struct nbd_reply reply;
|
590 |
|
591 |
TRACE("Reading request.");
|
592 |
|
593 |
if (nbd_receive_request(csock, &request) == -1) |
594 |
return -1; |
595 |
|
596 |
if (request.len + NBD_REPLY_SIZE > data_size) {
|
597 |
LOG("len (%u) is larger than max len (%u)",
|
598 |
request.len + NBD_REPLY_SIZE, data_size); |
599 |
errno = EINVAL; |
600 |
return -1; |
601 |
} |
602 |
|
603 |
if ((request.from + request.len) < request.from) {
|
604 |
LOG("integer overflow detected! "
|
605 |
"you're probably being attacked");
|
606 |
errno = EINVAL; |
607 |
return -1; |
608 |
} |
609 |
|
610 |
if ((request.from + request.len) > size) {
|
611 |
LOG("From: %" PRIu64 ", Len: %u, Size: %" PRIu64 |
612 |
", Offset: %" PRIu64 "\n", |
613 |
request.from, request.len, (uint64_t)size, dev_offset); |
614 |
LOG("requested operation past EOF--bad client?");
|
615 |
errno = EINVAL; |
616 |
return -1; |
617 |
} |
618 |
|
619 |
TRACE("Decoding type");
|
620 |
|
621 |
reply.handle = request.handle; |
622 |
reply.error = 0;
|
623 |
|
624 |
switch (request.type) {
|
625 |
case NBD_CMD_READ:
|
626 |
TRACE("Request type is READ");
|
627 |
|
628 |
if (bdrv_read(bs, (request.from + dev_offset) / 512, |
629 |
data + NBD_REPLY_SIZE, |
630 |
request.len / 512) == -1) { |
631 |
LOG("reading from file failed");
|
632 |
errno = EINVAL; |
633 |
return -1; |
634 |
} |
635 |
*offset += request.len; |
636 |
|
637 |
TRACE("Read %u byte(s)", request.len);
|
638 |
|
639 |
/* Reply
|
640 |
[ 0 .. 3] magic (NBD_REPLY_MAGIC)
|
641 |
[ 4 .. 7] error (0 == no error)
|
642 |
[ 7 .. 15] handle
|
643 |
*/
|
644 |
|
645 |
cpu_to_be32w((uint32_t*)data, NBD_REPLY_MAGIC); |
646 |
cpu_to_be32w((uint32_t*)(data + 4), reply.error);
|
647 |
cpu_to_be64w((uint64_t*)(data + 8), reply.handle);
|
648 |
|
649 |
TRACE("Sending data to client");
|
650 |
|
651 |
if (write_sync(csock, data,
|
652 |
request.len + NBD_REPLY_SIZE) != |
653 |
request.len + NBD_REPLY_SIZE) { |
654 |
LOG("writing to socket failed");
|
655 |
errno = EINVAL; |
656 |
return -1; |
657 |
} |
658 |
break;
|
659 |
case NBD_CMD_WRITE:
|
660 |
TRACE("Request type is WRITE");
|
661 |
|
662 |
TRACE("Reading %u byte(s)", request.len);
|
663 |
|
664 |
if (read_sync(csock, data, request.len) != request.len) {
|
665 |
LOG("reading from socket failed");
|
666 |
errno = EINVAL; |
667 |
return -1; |
668 |
} |
669 |
|
670 |
if (nbdflags & NBD_FLAG_READ_ONLY) {
|
671 |
TRACE("Server is read-only, return error");
|
672 |
reply.error = 1;
|
673 |
} else {
|
674 |
TRACE("Writing to device");
|
675 |
|
676 |
if (bdrv_write(bs, (request.from + dev_offset) / 512, |
677 |
data, request.len / 512) == -1) { |
678 |
LOG("writing to file failed");
|
679 |
errno = EINVAL; |
680 |
return -1; |
681 |
} |
682 |
|
683 |
*offset += request.len; |
684 |
} |
685 |
|
686 |
if (nbd_send_reply(csock, &reply) == -1) |
687 |
return -1; |
688 |
break;
|
689 |
case NBD_CMD_DISC:
|
690 |
TRACE("Request type is DISCONNECT");
|
691 |
errno = 0;
|
692 |
return 1; |
693 |
default:
|
694 |
LOG("invalid request type (%u) received", request.type);
|
695 |
errno = EINVAL; |
696 |
return -1; |
697 |
} |
698 |
|
699 |
TRACE("Request/Reply complete");
|
700 |
|
701 |
return 0; |
702 |
} |