662 lines
		
	
	
		
			14 KiB
		
	
	
	
		
			C
		
	
	
	
			
		
		
	
	
			662 lines
		
	
	
		
			14 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, write to the Free Software
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 *  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston MA  02110-1301 USA
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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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/* 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, &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, off_t *size, size_t *blocksize)
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{
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	char buf[8 + 8 + 8 + 128];
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	uint64_t magic;
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	TRACE("Receiving negotation.");
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	if (read_sync(csock, buf, sizeof(buf)) != sizeof(buf)) {
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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_cpup((uint64_t*)(buf + 8));
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	*size = be64_to_cpup((uint64_t*)(buf + 16));
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	*blocksize = 1024;
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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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	TRACE("Magic is 0x%" PRIx64, magic);
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	TRACE("Size is %" PRIu64, *size);
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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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	TRACE("Checking 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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        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 %llu block(s)",
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	      (unsigned long long)(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)) {
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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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 | 
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	/* Request
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	   [ 0 ..  3]   magic   (NBD_REQUEST_MAGIC)
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	   [ 4 ..  7]   type    (0 == READ, 1 == WRITE)
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	   [ 8 .. 15]   handle
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	   [16 .. 23]   from
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	   [24 .. 27]   len
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	 */
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	magic = be32_to_cpup((uint32_t*)buf);
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	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;
 | 
						|
}
 |