This patch allows to connect Qemu using NBD protocol to an nbd-server using named exports. For instance, if on the host "isoserver", in /etc/nbd-server/config, you have: [generic] [debian-500-ppc-netinst] exportname = /ISO/debian-500-powerpc-netinst.iso [Fedora-10-ppc-netinst] exportname = /ISO/Fedora-10-ppc-netinst.iso You can connect to it, using: qemu -cdrom nbd:isoserver:exportname=debian-500-ppc-netinst qemu -cdrom nbd:isoserver:exportname=Fedora-10-ppc-netinst NOTE: you need at least nbd-server 2.9.18 Signed-off-by: Laurent Vivier <laurent@vivier.eu> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
755 lines
16 KiB
C
755 lines
16 KiB
C
/*
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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 <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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#ifdef __sun__
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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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#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_REQUEST_MAGIC 0x25609513
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#define NBD_REPLY_MAGIC 0x67446698
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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 = 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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int tcp_socket_outgoing(const char *address, uint16_t port)
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{
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int s;
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struct in_addr in;
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struct sockaddr_in addr;
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s = socket(PF_INET, SOCK_STREAM, 0);
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if (s == -1) {
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return -1;
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}
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if (inet_aton(address, &in) == 0) {
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struct hostent *ent;
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ent = gethostbyname(address);
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if (ent == NULL) {
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goto error;
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}
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memcpy(&in, ent->h_addr, sizeof(in));
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}
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addr.sin_family = AF_INET;
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addr.sin_port = htons(port);
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memcpy(&addr.sin_addr.s_addr, &in, sizeof(in));
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if (connect(s, (struct sockaddr *)&addr, sizeof(addr)) == -1) {
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goto error;
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}
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return s;
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error:
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closesocket(s);
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return -1;
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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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int s;
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struct in_addr in;
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struct sockaddr_in addr;
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int opt;
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s = socket(PF_INET, SOCK_STREAM, 0);
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if (s == -1) {
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return -1;
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}
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if (inet_aton(address, &in) == 0) {
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struct hostent *ent;
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ent = gethostbyname(address);
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if (ent == NULL) {
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goto error;
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}
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memcpy(&in, ent->h_addr, sizeof(in));
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}
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addr.sin_family = AF_INET;
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addr.sin_port = htons(port);
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memcpy(&addr.sin_addr.s_addr, &in, sizeof(in));
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opt = 1;
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if (setsockopt(s, SOL_SOCKET, SO_REUSEADDR,
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(const void *) &opt, sizeof(opt)) == -1) {
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goto error;
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}
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if (bind(s, (struct sockaddr *)&addr, sizeof(addr)) == -1) {
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goto error;
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}
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if (listen(s, 128) == -1) {
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goto error;
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}
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return s;
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error:
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closesocket(s);
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return -1;
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}
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#ifndef _WIN32
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int unix_socket_incoming(const char *path)
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{
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int s;
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struct sockaddr_un addr;
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s = socket(PF_UNIX, SOCK_STREAM, 0);
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if (s == -1) {
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return -1;
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}
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memset(&addr, 0, sizeof(addr));
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addr.sun_family = AF_UNIX;
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pstrcpy(addr.sun_path, sizeof(addr.sun_path), path);
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if (bind(s, (struct sockaddr *)&addr, sizeof(addr)) == -1) {
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goto error;
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}
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if (listen(s, 128) == -1) {
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goto error;
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}
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return s;
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error:
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closesocket(s);
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return -1;
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}
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int unix_socket_outgoing(const char *path)
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{
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int s;
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struct sockaddr_un addr;
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s = socket(PF_UNIX, SOCK_STREAM, 0);
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if (s == -1) {
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return -1;
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}
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memset(&addr, 0, sizeof(addr));
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addr.sun_family = AF_UNIX;
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pstrcpy(addr.sun_path, sizeof(addr.sun_path), path);
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if (connect(s, (struct sockaddr *)&addr, sizeof(addr)) == -1) {
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goto error;
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}
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return s;
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error:
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closesocket(s);
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return -1;
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}
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#else
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int unix_socket_incoming(const char *path)
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{
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errno = ENOTSUP;
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return -1;
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}
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int unix_socket_outgoing(const char *path)
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{
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errno = ENOTSUP;
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return -1;
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}
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#endif
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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)
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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 .. 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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memset(buf + 24, 0, 128);
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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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#ifndef _WIN32
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int nbd_init(int fd, int csock, 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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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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TRACE("Setting size to %zd block(s)", (size_t)(size / blocksize));
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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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TRACE("Clearing NBD socket");
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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;
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return -1;
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}
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TRACE("Setting NBD socket");
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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;
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return -1;
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}
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TRACE("Negotiation ended");
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return 0;
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}
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int nbd_disconnect(int fd)
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{
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ioctl(fd, NBD_CLEAR_QUE);
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ioctl(fd, NBD_DISCONNECT);
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ioctl(fd, NBD_CLEAR_SOCK);
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return 0;
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}
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int nbd_client(int fd, int csock)
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{
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int ret;
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int serrno;
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TRACE("Doing NBD loop");
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ret = ioctl(fd, NBD_DO_IT);
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serrno = errno;
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TRACE("NBD loop returned %d: %s", ret, strerror(serrno));
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TRACE("Clearing NBD queue");
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ioctl(fd, NBD_CLEAR_QUE);
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TRACE("Clearing NBD socket");
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ioctl(fd, NBD_CLEAR_SOCK);
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errno = serrno;
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return ret;
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}
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#else
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int nbd_init(int fd, int csock, off_t size, size_t blocksize)
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{
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errno = ENOTSUP;
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return -1;
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}
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int nbd_disconnect(int fd)
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{
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errno = ENOTSUP;
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return -1;
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}
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int nbd_client(int fd, int csock)
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{
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errno = ENOTSUP;
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return -1;
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}
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#endif
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int nbd_send_request(int csock, struct nbd_request *request)
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{
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uint8_t buf[4 + 4 + 8 + 8 + 4];
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cpu_to_be32w((uint32_t*)buf, NBD_REQUEST_MAGIC);
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cpu_to_be32w((uint32_t*)(buf + 4), request->type);
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cpu_to_be64w((uint64_t*)(buf + 8), request->handle);
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cpu_to_be64w((uint64_t*)(buf + 16), request->from);
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cpu_to_be32w((uint32_t*)(buf + 24), request->len);
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TRACE("Sending request to client");
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if (write_sync(csock, buf, sizeof(buf)) != sizeof(buf)) {
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LOG("writing to socket failed");
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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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static int nbd_receive_request(int csock, struct nbd_request *request)
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{
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uint8_t buf[4 + 4 + 8 + 8 + 4];
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uint32_t magic;
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|
|
if (read_sync(csock, buf, sizeof(buf)) != sizeof(buf)) {
|
|
LOG("read failed");
|
|
errno = EINVAL;
|
|
return -1;
|
|
}
|
|
|
|
/* Request
|
|
[ 0 .. 3] magic (NBD_REQUEST_MAGIC)
|
|
[ 4 .. 7] type (0 == READ, 1 == WRITE)
|
|
[ 8 .. 15] handle
|
|
[16 .. 23] from
|
|
[24 .. 27] len
|
|
*/
|
|
|
|
magic = be32_to_cpup((uint32_t*)buf);
|
|
request->type = be32_to_cpup((uint32_t*)(buf + 4));
|
|
request->handle = be64_to_cpup((uint64_t*)(buf + 8));
|
|
request->from = be64_to_cpup((uint64_t*)(buf + 16));
|
|
request->len = be32_to_cpup((uint32_t*)(buf + 24));
|
|
|
|
TRACE("Got request: "
|
|
"{ magic = 0x%x, .type = %d, from = %" PRIu64" , len = %u }",
|
|
magic, request->type, request->from, request->len);
|
|
|
|
if (magic != NBD_REQUEST_MAGIC) {
|
|
LOG("invalid magic (got 0x%x)", magic);
|
|
errno = EINVAL;
|
|
return -1;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
int nbd_receive_reply(int csock, struct nbd_reply *reply)
|
|
{
|
|
uint8_t buf[4 + 4 + 8];
|
|
uint32_t magic;
|
|
|
|
memset(buf, 0xAA, sizeof(buf));
|
|
|
|
if (read_sync(csock, buf, sizeof(buf)) != sizeof(buf)) {
|
|
LOG("read failed");
|
|
errno = EINVAL;
|
|
return -1;
|
|
}
|
|
|
|
/* Reply
|
|
[ 0 .. 3] magic (NBD_REPLY_MAGIC)
|
|
[ 4 .. 7] error (0 == no error)
|
|
[ 7 .. 15] handle
|
|
*/
|
|
|
|
magic = be32_to_cpup((uint32_t*)buf);
|
|
reply->error = be32_to_cpup((uint32_t*)(buf + 4));
|
|
reply->handle = be64_to_cpup((uint64_t*)(buf + 8));
|
|
|
|
TRACE("Got reply: "
|
|
"{ magic = 0x%x, .error = %d, handle = %" PRIu64" }",
|
|
magic, reply->error, reply->handle);
|
|
|
|
if (magic != NBD_REPLY_MAGIC) {
|
|
LOG("invalid magic (got 0x%x)", magic);
|
|
errno = EINVAL;
|
|
return -1;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static int nbd_send_reply(int csock, struct nbd_reply *reply)
|
|
{
|
|
uint8_t buf[4 + 4 + 8];
|
|
|
|
/* Reply
|
|
[ 0 .. 3] magic (NBD_REPLY_MAGIC)
|
|
[ 4 .. 7] error (0 == no error)
|
|
[ 7 .. 15] handle
|
|
*/
|
|
cpu_to_be32w((uint32_t*)buf, NBD_REPLY_MAGIC);
|
|
cpu_to_be32w((uint32_t*)(buf + 4), reply->error);
|
|
cpu_to_be64w((uint64_t*)(buf + 8), reply->handle);
|
|
|
|
TRACE("Sending response to client");
|
|
|
|
if (write_sync(csock, buf, sizeof(buf)) != sizeof(buf)) {
|
|
LOG("writing to socket failed");
|
|
errno = EINVAL;
|
|
return -1;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
int nbd_trip(BlockDriverState *bs, int csock, off_t size, uint64_t dev_offset,
|
|
off_t *offset, bool readonly, uint8_t *data, int data_size)
|
|
{
|
|
struct nbd_request request;
|
|
struct nbd_reply reply;
|
|
|
|
TRACE("Reading request.");
|
|
|
|
if (nbd_receive_request(csock, &request) == -1)
|
|
return -1;
|
|
|
|
if (request.len > data_size) {
|
|
LOG("len (%u) is larger than max len (%u)",
|
|
request.len, data_size);
|
|
errno = EINVAL;
|
|
return -1;
|
|
}
|
|
|
|
if ((request.from + request.len) < request.from) {
|
|
LOG("integer overflow detected! "
|
|
"you're probably being attacked");
|
|
errno = EINVAL;
|
|
return -1;
|
|
}
|
|
|
|
if ((request.from + request.len) > size) {
|
|
LOG("From: %" PRIu64 ", Len: %u, Size: %" PRIu64
|
|
", Offset: %" PRIu64 "\n",
|
|
request.from, request.len, (uint64_t)size, dev_offset);
|
|
LOG("requested operation past EOF--bad client?");
|
|
errno = EINVAL;
|
|
return -1;
|
|
}
|
|
|
|
TRACE("Decoding type");
|
|
|
|
reply.handle = request.handle;
|
|
reply.error = 0;
|
|
|
|
switch (request.type) {
|
|
case NBD_CMD_READ:
|
|
TRACE("Request type is READ");
|
|
|
|
if (bdrv_read(bs, (request.from + dev_offset) / 512, data,
|
|
request.len / 512) == -1) {
|
|
LOG("reading from file failed");
|
|
errno = EINVAL;
|
|
return -1;
|
|
}
|
|
*offset += request.len;
|
|
|
|
TRACE("Read %u byte(s)", request.len);
|
|
|
|
if (nbd_send_reply(csock, &reply) == -1)
|
|
return -1;
|
|
|
|
TRACE("Sending data to client");
|
|
|
|
if (write_sync(csock, data, request.len) != request.len) {
|
|
LOG("writing to socket failed");
|
|
errno = EINVAL;
|
|
return -1;
|
|
}
|
|
break;
|
|
case NBD_CMD_WRITE:
|
|
TRACE("Request type is WRITE");
|
|
|
|
TRACE("Reading %u byte(s)", request.len);
|
|
|
|
if (read_sync(csock, data, request.len) != request.len) {
|
|
LOG("reading from socket failed");
|
|
errno = EINVAL;
|
|
return -1;
|
|
}
|
|
|
|
if (readonly) {
|
|
TRACE("Server is read-only, return error");
|
|
reply.error = 1;
|
|
} else {
|
|
TRACE("Writing to device");
|
|
|
|
if (bdrv_write(bs, (request.from + dev_offset) / 512,
|
|
data, request.len / 512) == -1) {
|
|
LOG("writing to file failed");
|
|
errno = EINVAL;
|
|
return -1;
|
|
}
|
|
|
|
*offset += request.len;
|
|
}
|
|
|
|
if (nbd_send_reply(csock, &reply) == -1)
|
|
return -1;
|
|
break;
|
|
case NBD_CMD_DISC:
|
|
TRACE("Request type is DISCONNECT");
|
|
errno = 0;
|
|
return 1;
|
|
default:
|
|
LOG("invalid request type (%u) received", request.type);
|
|
errno = EINVAL;
|
|
return -1;
|
|
}
|
|
|
|
TRACE("Request/Reply complete");
|
|
|
|
return 0;
|
|
}
|