[mirror_qemu.git] / nbd.c

/*
 *  Copyright (C) 2005  Anthony Liguori <anthony@codemonkey.ws>
 *
 *  Network Block Device
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; under version 2 of the License.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, write to the Free Software
 *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

#include "nbd.h"

#include <errno.h>
#include <string.h>
#ifndef _WIN32
#include <sys/ioctl.h>
#endif
#ifdef __sun__
#include <sys/ioccom.h>
#endif
#include <ctype.h>
#include <inttypes.h>

#include "qemu_socket.h"

//#define DEBUG_NBD

#ifdef DEBUG_NBD
#define TRACE(msg, ...) do { \
    LOG(msg, ## __VA_ARGS__); \
} while(0)
#else
#define TRACE(msg, ...) \
    do { } while (0)
#endif

#define LOG(msg, ...) do { \
    fprintf(stderr, "%s:%s():L%d: " msg "\n", \
            __FILE__, __FUNCTION__, __LINE__, ## __VA_ARGS__); \
} while(0)

/* This is all part of the "official" NBD API */

#define NBD_REQUEST_MAGIC       0x25609513
#define NBD_REPLY_MAGIC         0x67446698

#define NBD_SET_SOCK            _IO(0xab, 0)
#define NBD_SET_BLKSIZE         _IO(0xab, 1)
#define NBD_SET_SIZE            _IO(0xab, 2)
#define NBD_DO_IT               _IO(0xab, 3)
#define NBD_CLEAR_SOCK          _IO(0xab, 4)
#define NBD_CLEAR_QUE           _IO(0xab, 5)
#define NBD_PRINT_DEBUG	        _IO(0xab, 6)
#define NBD_SET_SIZE_BLOCKS	_IO(0xab, 7)
#define NBD_DISCONNECT          _IO(0xab, 8)

/* That's all folks */

#define read_sync(fd, buffer, size) nbd_wr_sync(fd, buffer, size, true)
#define write_sync(fd, buffer, size) nbd_wr_sync(fd, buffer, size, false)

size_t nbd_wr_sync(int fd, void *buffer, size_t size, bool do_read)
{
    size_t offset = 0;

    while (offset < size) {
        ssize_t len;

        if (do_read) {
            len = recv(fd, buffer + offset, size - offset, 0);
        } else {
            len = send(fd, buffer + offset, size - offset, 0);
        }

        if (len == -1)
            errno = socket_error();

        /* recoverable error */
        if (len == -1 && (errno == EAGAIN || errno == EINTR)) {
            continue;
        }

        /* eof */
        if (len == 0) {
            break;
        }

        /* unrecoverable error */
        if (len == -1) {
            return 0;
        }

        offset += len;
    }

    return offset;
}

int tcp_socket_outgoing(const char *address, uint16_t port)
{
    int s;
    struct in_addr in;
    struct sockaddr_in addr;

    s = socket(PF_INET, SOCK_STREAM, 0);
    if (s == -1) {
        return -1;
    }

    if (inet_aton(address, &in) == 0) {
        struct hostent *ent;

        ent = gethostbyname(address);
        if (ent == NULL) {
            goto error;
        }

        memcpy(&in, ent->h_addr, sizeof(in));
    }

    addr.sin_family = AF_INET;
    addr.sin_port = htons(port);
    memcpy(&addr.sin_addr.s_addr, &in, sizeof(in));

    if (connect(s, (struct sockaddr *)&addr, sizeof(addr)) == -1) {
        goto error;
    }

    return s;
error:
    closesocket(s);
    return -1;
}

int tcp_socket_incoming(const char *address, uint16_t port)
{
    int s;
    struct in_addr in;
    struct sockaddr_in addr;
    int opt;

    s = socket(PF_INET, SOCK_STREAM, 0);
    if (s == -1) {
        return -1;
    }

    if (inet_aton(address, &in) == 0) {
        struct hostent *ent;

        ent = gethostbyname(address);
        if (ent == NULL) {
            goto error;
        }

        memcpy(&in, ent->h_addr, sizeof(in));
    }

    addr.sin_family = AF_INET;
    addr.sin_port = htons(port);
    memcpy(&addr.sin_addr.s_addr, &in, sizeof(in));

    opt = 1;
    if (setsockopt(s, SOL_SOCKET, SO_REUSEADDR, &opt, sizeof(opt)) == -1) {
        goto error;
    }

    if (bind(s, (struct sockaddr *)&addr, sizeof(addr)) == -1) {
        goto error;
    }

    if (listen(s, 128) == -1) {
        goto error;
    }

    return s;
error:
    closesocket(s);
    return -1;
}

#ifndef _WIN32
int unix_socket_incoming(const char *path)
{
    int s;
    struct sockaddr_un addr;

    s = socket(PF_UNIX, SOCK_STREAM, 0);
    if (s == -1) {
        return -1;
    }

    memset(&addr, 0, sizeof(addr));
    addr.sun_family = AF_UNIX;
    pstrcpy(addr.sun_path, sizeof(addr.sun_path), path);

    if (bind(s, (struct sockaddr *)&addr, sizeof(addr)) == -1) {
        goto error;
    }

    if (listen(s, 128) == -1) {
        goto error;
    }

    return s;
error:
    closesocket(s);
    return -1;
}

int unix_socket_outgoing(const char *path)
{
    int s;
    struct sockaddr_un addr;

    s = socket(PF_UNIX, SOCK_STREAM, 0);
    if (s == -1) {
        return -1;
    }

    memset(&addr, 0, sizeof(addr));
    addr.sun_family = AF_UNIX;
    pstrcpy(addr.sun_path, sizeof(addr.sun_path), path);

    if (connect(s, (struct sockaddr *)&addr, sizeof(addr)) == -1) {
        goto error;
    }

    return s;
error:
    closesocket(s);
    return -1;
}
#else
int unix_socket_incoming(const char *path)
{
    errno = ENOTSUP;
    return -1;
}

int unix_socket_outgoing(const char *path)
{
    errno = ENOTSUP;
    return -1;
}
#endif


/* Basic flow

   Server         Client

   Negotiate
                  Request
   Response
                  Request
   Response
                  ...
   ...
                  Request (type == 2)
*/

int nbd_negotiate(int csock, off_t size)
{
	char buf[8 + 8 + 8 + 128];

	/* Negotiate
	   [ 0 ..   7]   passwd   ("NBDMAGIC")
	   [ 8 ..  15]   magic    (0x00420281861253)
	   [16 ..  23]   size
	   [24 .. 151]   reserved (0)
	 */

	TRACE("Beginning negotiation.");
	memcpy(buf, "NBDMAGIC", 8);
	cpu_to_be64w((uint64_t*)(buf + 8), 0x00420281861253LL);
	cpu_to_be64w((uint64_t*)(buf + 16), size);
	memset(buf + 24, 0, 128);

	if (write_sync(csock, buf, sizeof(buf)) != sizeof(buf)) {
		LOG("write failed");
		errno = EINVAL;
		return -1;
	}

	TRACE("Negotation succeeded.");

	return 0;
}

int nbd_receive_negotiate(int csock, off_t *size, size_t *blocksize)
{
	char buf[8 + 8 + 8 + 128];
	uint64_t magic;

	TRACE("Receiving negotation.");

	if (read_sync(csock, buf, sizeof(buf)) != sizeof(buf)) {
		LOG("read failed");
		errno = EINVAL;
		return -1;
	}

	magic = be64_to_cpup((uint64_t*)(buf + 8));
	*size = be64_to_cpup((uint64_t*)(buf + 16));
	*blocksize = 1024;

	TRACE("Magic is %c%c%c%c%c%c%c%c",
	      qemu_isprint(buf[0]) ? buf[0] : '.',
	      qemu_isprint(buf[1]) ? buf[1] : '.',
	      qemu_isprint(buf[2]) ? buf[2] : '.',
	      qemu_isprint(buf[3]) ? buf[3] : '.',
	      qemu_isprint(buf[4]) ? buf[4] : '.',
	      qemu_isprint(buf[5]) ? buf[5] : '.',
	      qemu_isprint(buf[6]) ? buf[6] : '.',
	      qemu_isprint(buf[7]) ? buf[7] : '.');
	TRACE("Magic is 0x%" PRIx64, magic);
	TRACE("Size is %" PRIu64, *size);

	if (memcmp(buf, "NBDMAGIC", 8) != 0) {
		LOG("Invalid magic received");
		errno = EINVAL;
		return -1;
	}

	TRACE("Checking magic");

	if (magic != 0x00420281861253LL) {
		LOG("Bad magic received");
		errno = EINVAL;
		return -1;
	}
        return 0;
}

#ifndef _WIN32
int nbd_init(int fd, int csock, off_t size, size_t blocksize)
{
	TRACE("Setting block size to %lu", (unsigned long)blocksize);

	if (ioctl(fd, NBD_SET_BLKSIZE, blocksize) == -1) {
		int serrno = errno;
		LOG("Failed setting NBD block size");
		errno = serrno;
		return -1;
	}

	TRACE("Setting size to %llu block(s)",
	      (unsigned long long)(size / blocksize));

	if (ioctl(fd, NBD_SET_SIZE_BLOCKS, size / blocksize) == -1) {
		int serrno = errno;
		LOG("Failed setting size (in blocks)");
		errno = serrno;
		return -1;
	}

	TRACE("Clearing NBD socket");

	if (ioctl(fd, NBD_CLEAR_SOCK) == -1) {
		int serrno = errno;
		LOG("Failed clearing NBD socket");
		errno = serrno;
		return -1;
	}

	TRACE("Setting NBD socket");

	if (ioctl(fd, NBD_SET_SOCK, csock) == -1) {
		int serrno = errno;
		LOG("Failed to set NBD socket");
		errno = serrno;
		return -1;
	}

	TRACE("Negotiation ended");

	return 0;
}

int nbd_disconnect(int fd)
{
	ioctl(fd, NBD_CLEAR_QUE);
	ioctl(fd, NBD_DISCONNECT);
	ioctl(fd, NBD_CLEAR_SOCK);
	return 0;
}

int nbd_client(int fd, int csock)
{
	int ret;
	int serrno;

	TRACE("Doing NBD loop");

	ret = ioctl(fd, NBD_DO_IT);
	serrno = errno;

	TRACE("NBD loop returned %d: %s", ret, strerror(serrno));

	TRACE("Clearing NBD queue");
	ioctl(fd, NBD_CLEAR_QUE);

	TRACE("Clearing NBD socket");
	ioctl(fd, NBD_CLEAR_SOCK);

	errno = serrno;
	return ret;
}
#else
int nbd_init(int fd, int csock, off_t size, size_t blocksize)
{
    errno = ENOTSUP;
    return -1;
}

int nbd_disconnect(int fd)
{
    errno = ENOTSUP;
    return -1;
}

int nbd_client(int fd, int csock)
{
    errno = ENOTSUP;
    return -1;
}
#endif

int nbd_send_request(int csock, struct nbd_request *request)
{
	uint8_t buf[4 + 4 + 8 + 8 + 4];

	cpu_to_be32w((uint32_t*)buf, NBD_REQUEST_MAGIC);
	cpu_to_be32w((uint32_t*)(buf + 4), request->type);
	cpu_to_be64w((uint64_t*)(buf + 8), request->handle);
	cpu_to_be64w((uint64_t*)(buf + 16), request->from);
	cpu_to_be32w((uint32_t*)(buf + 24), request->len);

	TRACE("Sending request to client");

	if (write_sync(csock, buf, sizeof(buf)) != sizeof(buf)) {
		LOG("writing to socket failed");
		errno = EINVAL;
		return -1;
	}
	return 0;
}


static int nbd_receive_request(int csock, struct nbd_request *request)
{
	uint8_t buf[4 + 4 + 8 + 8 + 4];
	uint32_t magic;

	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, 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;
}
Commit	Line	Data
	1	/*
	2	* Copyright (C) 2005 Anthony Liguori <anthony@codemonkey.ws>
	3	*
	4	* Network Block Device
	5	*
	6	* This program is free software; you can redistribute it and/or modify
	7	* it under the terms of the GNU General Public License as published by
	8	* the Free Software Foundation; under version 2 of the License.
	9	*
	10	* This program is distributed in the hope that it will be useful,
	11	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	12	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	13	* GNU General Public License for more details.
	14	*
	15	* You should have received a copy of the GNU General Public License
	16	* along with this program; if not, write to the Free Software
	17	* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
	18	*/
	19
	20	#include "nbd.h"
	21
	22	#include <errno.h>
	23	#include <string.h>
	24	#ifndef _WIN32
	25	#include <sys/ioctl.h>
	26	#endif
	27	#ifdef __sun__
	28	#include <sys/ioccom.h>
	29	#endif
	30	#include <ctype.h>
	31	#include <inttypes.h>
	32
	33	#include "qemu_socket.h"
	34
	35	//#define DEBUG_NBD
	36
	37	#ifdef DEBUG_NBD
	38	#define TRACE(msg, ...) do { \
	39	LOG(msg, ## __VA_ARGS__); \
	40	} while(0)
	41	#else
	42	#define TRACE(msg, ...) \
	43	do { } while (0)
	44	#endif
	45
	46	#define LOG(msg, ...) do { \
	47	fprintf(stderr, "%s:%s():L%d: " msg "\n", \
	48	__FILE__, __FUNCTION__, __LINE__, ## __VA_ARGS__); \
	49	} while(0)
	50
	51	/* This is all part of the "official" NBD API */
	52
	53	#define NBD_REQUEST_MAGIC 0x25609513
	54	#define NBD_REPLY_MAGIC 0x67446698
	55
	56	#define NBD_SET_SOCK _IO(0xab, 0)
	57	#define NBD_SET_BLKSIZE _IO(0xab, 1)
	58	#define NBD_SET_SIZE _IO(0xab, 2)
	59	#define NBD_DO_IT _IO(0xab, 3)
	60	#define NBD_CLEAR_SOCK _IO(0xab, 4)
	61	#define NBD_CLEAR_QUE _IO(0xab, 5)
	62	#define NBD_PRINT_DEBUG _IO(0xab, 6)
	63	#define NBD_SET_SIZE_BLOCKS _IO(0xab, 7)
	64	#define NBD_DISCONNECT _IO(0xab, 8)
	65
	66	/* That's all folks */
	67
	68	#define read_sync(fd, buffer, size) nbd_wr_sync(fd, buffer, size, true)
	69	#define write_sync(fd, buffer, size) nbd_wr_sync(fd, buffer, size, false)
	70
	71	size_t nbd_wr_sync(int fd, void *buffer, size_t size, bool do_read)
	72	{
	73	size_t offset = 0;
	74
	75	while (offset < size) {
	76	ssize_t len;
	77
	78	if (do_read) {
	79	len = recv(fd, buffer + offset, size - offset, 0);
	80	} else {
	81	len = send(fd, buffer + offset, size - offset, 0);
	82	}
	83
	84	if (len == -1)
	85	errno = socket_error();
	86
	87	/* recoverable error */
	88	if (len == -1 && (errno == EAGAIN \|\| errno == EINTR)) {
	89	continue;
	90	}
	91
	92	/* eof */
	93	if (len == 0) {
	94	break;
	95	}
	96
	97	/* unrecoverable error */
	98	if (len == -1) {
	99	return 0;
	100	}
	101
	102	offset += len;
	103	}
	104
	105	return offset;
	106	}
	107
	108	int tcp_socket_outgoing(const char *address, uint16_t port)
	109	{
	110	int s;
	111	struct in_addr in;
	112	struct sockaddr_in addr;
	113
	114	s = socket(PF_INET, SOCK_STREAM, 0);
	115	if (s == -1) {
	116	return -1;
	117	}
	118
	119	if (inet_aton(address, &in) == 0) {
	120	struct hostent *ent;
	121
	122	ent = gethostbyname(address);
	123	if (ent == NULL) {
	124	goto error;
	125	}
	126
	127	memcpy(&in, ent->h_addr, sizeof(in));
	128	}
	129
	130	addr.sin_family = AF_INET;
	131	addr.sin_port = htons(port);
	132	memcpy(&addr.sin_addr.s_addr, &in, sizeof(in));
	133
	134	if (connect(s, (struct sockaddr *)&addr, sizeof(addr)) == -1) {
	135	goto error;
	136	}
	137
	138	return s;
	139	error:
	140	closesocket(s);
	141	return -1;
	142	}
	143
	144	int tcp_socket_incoming(const char *address, uint16_t port)
	145	{
	146	int s;
	147	struct in_addr in;
	148	struct sockaddr_in addr;
	149	int opt;
	150
	151	s = socket(PF_INET, SOCK_STREAM, 0);
	152	if (s == -1) {
	153	return -1;
	154	}
	155
	156	if (inet_aton(address, &in) == 0) {
	157	struct hostent *ent;
	158
	159	ent = gethostbyname(address);
	160	if (ent == NULL) {
	161	goto error;
	162	}
	163
	164	memcpy(&in, ent->h_addr, sizeof(in));
	165	}
	166
	167	addr.sin_family = AF_INET;
	168	addr.sin_port = htons(port);
	169	memcpy(&addr.sin_addr.s_addr, &in, sizeof(in));
	170
	171	opt = 1;
	172	if (setsockopt(s, SOL_SOCKET, SO_REUSEADDR, &opt, sizeof(opt)) == -1) {
	173	goto error;
	174	}
	175
	176	if (bind(s, (struct sockaddr *)&addr, sizeof(addr)) == -1) {
	177	goto error;
	178	}
	179
	180	if (listen(s, 128) == -1) {
	181	goto error;
	182	}
	183
	184	return s;
	185	error:
	186	closesocket(s);
	187	return -1;
	188	}
	189
	190	#ifndef _WIN32
	191	int unix_socket_incoming(const char *path)
	192	{
	193	int s;
	194	struct sockaddr_un addr;
	195
	196	s = socket(PF_UNIX, SOCK_STREAM, 0);
	197	if (s == -1) {
	198	return -1;
	199	}
	200
	201	memset(&addr, 0, sizeof(addr));
	202	addr.sun_family = AF_UNIX;
	203	pstrcpy(addr.sun_path, sizeof(addr.sun_path), path);
	204
	205	if (bind(s, (struct sockaddr *)&addr, sizeof(addr)) == -1) {
	206	goto error;
	207	}
	208
	209	if (listen(s, 128) == -1) {
	210	goto error;
	211	}
	212
	213	return s;
	214	error:
	215	closesocket(s);
	216	return -1;
	217	}
	218
	219	int unix_socket_outgoing(const char *path)
	220	{
	221	int s;
	222	struct sockaddr_un addr;
	223
	224	s = socket(PF_UNIX, SOCK_STREAM, 0);
	225	if (s == -1) {
	226	return -1;
	227	}
	228
	229	memset(&addr, 0, sizeof(addr));
	230	addr.sun_family = AF_UNIX;
	231	pstrcpy(addr.sun_path, sizeof(addr.sun_path), path);
	232
	233	if (connect(s, (struct sockaddr *)&addr, sizeof(addr)) == -1) {
	234	goto error;
	235	}
	236
	237	return s;
	238	error:
	239	closesocket(s);
	240	return -1;
	241	}
	242	#else
	243	int unix_socket_incoming(const char *path)
	244	{
	245	errno = ENOTSUP;
	246	return -1;
	247	}
	248
	249	int unix_socket_outgoing(const char *path)
	250	{
	251	errno = ENOTSUP;
	252	return -1;
	253	}
	254	#endif
	255
	256
	257	/* Basic flow
	258
	259	Server Client
	260
	261	Negotiate
	262	Request
	263	Response
	264	Request
	265	Response
	266	...
	267	...
	268	Request (type == 2)
	269	*/
	270
	271	int nbd_negotiate(int csock, off_t size)
	272	{
	273	char buf[8 + 8 + 8 + 128];
	274
	275	/* Negotiate
	276	[ 0 .. 7] passwd ("NBDMAGIC")
	277	[ 8 .. 15] magic (0x00420281861253)
	278	[16 .. 23] size
	279	[24 .. 151] reserved (0)
	280	*/
	281
	282	TRACE("Beginning negotiation.");
	283	memcpy(buf, "NBDMAGIC", 8);
	284	cpu_to_be64w((uint64_t*)(buf + 8), 0x00420281861253LL);
	285	cpu_to_be64w((uint64_t*)(buf + 16), size);
	286	memset(buf + 24, 0, 128);
	287
	288	if (write_sync(csock, buf, sizeof(buf)) != sizeof(buf)) {
	289	LOG("write failed");
	290	errno = EINVAL;
	291	return -1;
	292	}
	293
	294	TRACE("Negotation succeeded.");
	295
	296	return 0;
	297	}
	298
	299	int nbd_receive_negotiate(int csock, off_t size, size_t blocksize)
	300	{
	301	char buf[8 + 8 + 8 + 128];
	302	uint64_t magic;
	303
	304	TRACE("Receiving negotation.");
	305
	306	if (read_sync(csock, buf, sizeof(buf)) != sizeof(buf)) {
	307	LOG("read failed");
	308	errno = EINVAL;
	309	return -1;
	310	}
	311
	312	magic = be64_to_cpup((uint64_t*)(buf + 8));
	313	size = be64_to_cpup((uint64_t)(buf + 16));
	314	*blocksize = 1024;
	315
	316	TRACE("Magic is %c%c%c%c%c%c%c%c",
	317	qemu_isprint(buf[0]) ? buf[0] : '.',
	318	qemu_isprint(buf[1]) ? buf[1] : '.',
	319	qemu_isprint(buf[2]) ? buf[2] : '.',
	320	qemu_isprint(buf[3]) ? buf[3] : '.',
	321	qemu_isprint(buf[4]) ? buf[4] : '.',
	322	qemu_isprint(buf[5]) ? buf[5] : '.',
	323	qemu_isprint(buf[6]) ? buf[6] : '.',
	324	qemu_isprint(buf[7]) ? buf[7] : '.');
	325	TRACE("Magic is 0x%" PRIx64, magic);
	326	TRACE("Size is %" PRIu64, *size);
	327
	328	if (memcmp(buf, "NBDMAGIC", 8) != 0) {
	329	LOG("Invalid magic received");
	330	errno = EINVAL;
	331	return -1;
	332	}
	333
	334	TRACE("Checking magic");
	335
	336	if (magic != 0x00420281861253LL) {
	337	LOG("Bad magic received");
	338	errno = EINVAL;
	339	return -1;
	340	}
	341	return 0;
	342	}
	343
	344	#ifndef _WIN32
	345	int nbd_init(int fd, int csock, off_t size, size_t blocksize)
	346	{
	347	TRACE("Setting block size to %lu", (unsigned long)blocksize);
	348
	349	if (ioctl(fd, NBD_SET_BLKSIZE, blocksize) == -1) {
	350	int serrno = errno;
	351	LOG("Failed setting NBD block size");
	352	errno = serrno;
	353	return -1;
	354	}
	355
	356	TRACE("Setting size to %llu block(s)",
	357	(unsigned long long)(size / blocksize));
	358
	359	if (ioctl(fd, NBD_SET_SIZE_BLOCKS, size / blocksize) == -1) {
	360	int serrno = errno;
	361	LOG("Failed setting size (in blocks)");
	362	errno = serrno;
	363	return -1;
	364	}
	365
	366	TRACE("Clearing NBD socket");
	367
	368	if (ioctl(fd, NBD_CLEAR_SOCK) == -1) {
	369	int serrno = errno;
	370	LOG("Failed clearing NBD socket");
	371	errno = serrno;
	372	return -1;
	373	}
	374
	375	TRACE("Setting NBD socket");
	376
	377	if (ioctl(fd, NBD_SET_SOCK, csock) == -1) {
	378	int serrno = errno;
	379	LOG("Failed to set NBD socket");
	380	errno = serrno;
	381	return -1;
	382	}
	383
	384	TRACE("Negotiation ended");
	385
	386	return 0;
	387	}
	388
	389	int nbd_disconnect(int fd)
	390	{
	391	ioctl(fd, NBD_CLEAR_QUE);
	392	ioctl(fd, NBD_DISCONNECT);
	393	ioctl(fd, NBD_CLEAR_SOCK);
	394	return 0;
	395	}
	396
	397	int nbd_client(int fd, int csock)
	398	{
	399	int ret;
	400	int serrno;
	401
	402	TRACE("Doing NBD loop");
	403
	404	ret = ioctl(fd, NBD_DO_IT);
	405	serrno = errno;
	406
	407	TRACE("NBD loop returned %d: %s", ret, strerror(serrno));
	408
	409	TRACE("Clearing NBD queue");
	410	ioctl(fd, NBD_CLEAR_QUE);
	411
	412	TRACE("Clearing NBD socket");
	413	ioctl(fd, NBD_CLEAR_SOCK);
	414
	415	errno = serrno;
	416	return ret;
	417	}
	418	#else
	419	int nbd_init(int fd, int csock, off_t size, size_t blocksize)
	420	{
	421	errno = ENOTSUP;
	422	return -1;
	423	}
	424
	425	int nbd_disconnect(int fd)
	426	{
	427	errno = ENOTSUP;
	428	return -1;
	429	}
	430
	431	int nbd_client(int fd, int csock)
	432	{
	433	errno = ENOTSUP;
	434	return -1;
	435	}
	436	#endif
	437
	438	int nbd_send_request(int csock, struct nbd_request *request)
	439	{
	440	uint8_t buf[4 + 4 + 8 + 8 + 4];
	441
	442	cpu_to_be32w((uint32_t*)buf, NBD_REQUEST_MAGIC);
	443	cpu_to_be32w((uint32_t*)(buf + 4), request->type);
	444	cpu_to_be64w((uint64_t*)(buf + 8), request->handle);
	445	cpu_to_be64w((uint64_t*)(buf + 16), request->from);
	446	cpu_to_be32w((uint32_t*)(buf + 24), request->len);
	447
	448	TRACE("Sending request to client");
	449
	450	if (write_sync(csock, buf, sizeof(buf)) != sizeof(buf)) {
	451	LOG("writing to socket failed");
	452	errno = EINVAL;
	453	return -1;
	454	}
	455	return 0;
	456	}
	457
	458
	459	static int nbd_receive_request(int csock, struct nbd_request *request)
	460	{
	461	uint8_t buf[4 + 4 + 8 + 8 + 4];
	462	uint32_t magic;
	463
	464	if (read_sync(csock, buf, sizeof(buf)) != sizeof(buf)) {
	465	LOG("read failed");
	466	errno = EINVAL;
	467	return -1;
	468	}
	469
	470	/* Request
	471	[ 0 .. 3] magic (NBD_REQUEST_MAGIC)
	472	[ 4 .. 7] type (0 == READ, 1 == WRITE)
	473	[ 8 .. 15] handle
	474	[16 .. 23] from
	475	[24 .. 27] len
	476	*/
	477
	478	magic = be32_to_cpup((uint32_t*)buf);
	479	request->type = be32_to_cpup((uint32_t*)(buf + 4));
	480	request->handle = be64_to_cpup((uint64_t*)(buf + 8));
	481	request->from = be64_to_cpup((uint64_t*)(buf + 16));
	482	request->len = be32_to_cpup((uint32_t*)(buf + 24));
	483
	484	TRACE("Got request: "
	485	"{ magic = 0x%x, .type = %d, from = %" PRIu64" , len = %u }",
	486	magic, request->type, request->from, request->len);
	487
	488	if (magic != NBD_REQUEST_MAGIC) {
	489	LOG("invalid magic (got 0x%x)", magic);
	490	errno = EINVAL;
	491	return -1;
	492	}
	493	return 0;
	494	}
	495
	496	int nbd_receive_reply(int csock, struct nbd_reply *reply)
	497	{
	498	uint8_t buf[4 + 4 + 8];
	499	uint32_t magic;
	500
	501	memset(buf, 0xAA, sizeof(buf));
	502
	503	if (read_sync(csock, buf, sizeof(buf)) != sizeof(buf)) {
	504	LOG("read failed");
	505	errno = EINVAL;
	506	return -1;
	507	}
	508
	509	/* Reply
	510	[ 0 .. 3] magic (NBD_REPLY_MAGIC)
	511	[ 4 .. 7] error (0 == no error)
	512	[ 7 .. 15] handle
	513	*/
	514
	515	magic = be32_to_cpup((uint32_t*)buf);
	516	reply->error = be32_to_cpup((uint32_t*)(buf + 4));
	517	reply->handle = be64_to_cpup((uint64_t*)(buf + 8));
	518
	519	TRACE("Got reply: "
	520	"{ magic = 0x%x, .error = %d, handle = %" PRIu64" }",
	521	magic, reply->error, reply->handle);
	522
	523	if (magic != NBD_REPLY_MAGIC) {
	524	LOG("invalid magic (got 0x%x)", magic);
	525	errno = EINVAL;
	526	return -1;
	527	}
	528	return 0;
	529	}
	530
	531	static int nbd_send_reply(int csock, struct nbd_reply *reply)
	532	{
	533	uint8_t buf[4 + 4 + 8];
	534
	535	/* Reply
	536	[ 0 .. 3] magic (NBD_REPLY_MAGIC)
	537	[ 4 .. 7] error (0 == no error)
	538	[ 7 .. 15] handle
	539	*/
	540	cpu_to_be32w((uint32_t*)buf, NBD_REPLY_MAGIC);
	541	cpu_to_be32w((uint32_t*)(buf + 4), reply->error);
	542	cpu_to_be64w((uint64_t*)(buf + 8), reply->handle);
	543
	544	TRACE("Sending response to client");
	545
	546	if (write_sync(csock, buf, sizeof(buf)) != sizeof(buf)) {
	547	LOG("writing to socket failed");
	548	errno = EINVAL;
	549	return -1;
	550	}
	551	return 0;
	552	}
	553
	554	int nbd_trip(BlockDriverState *bs, int csock, off_t size, uint64_t dev_offset,
	555	off_t offset, bool readonly, uint8_t data, int data_size)
	556	{
	557	struct nbd_request request;
	558	struct nbd_reply reply;
	559
	560	TRACE("Reading request.");
	561
	562	if (nbd_receive_request(csock, &request) == -1)
	563	return -1;
	564
	565	if (request.len > data_size) {
	566	LOG("len (%u) is larger than max len (%u)",
	567	request.len, data_size);
	568	errno = EINVAL;
	569	return -1;
	570	}
	571
	572	if ((request.from + request.len) < request.from) {
	573	LOG("integer overflow detected! "
	574	"you're probably being attacked");
	575	errno = EINVAL;
	576	return -1;
	577	}
	578
	579	if ((request.from + request.len) > size) {
	580	LOG("From: %" PRIu64 ", Len: %u, Size: %" PRIu64
	581	", Offset: %" PRIu64 "\n",
	582	request.from, request.len, size, dev_offset);
	583	LOG("requested operation past EOF--bad client?");
	584	errno = EINVAL;
	585	return -1;
	586	}
	587
	588	TRACE("Decoding type");
	589
	590	reply.handle = request.handle;
	591	reply.error = 0;
	592
	593	switch (request.type) {
	594	case NBD_CMD_READ:
	595	TRACE("Request type is READ");
	596
	597	if (bdrv_read(bs, (request.from + dev_offset) / 512, data,
	598	request.len / 512) == -1) {
	599	LOG("reading from file failed");
	600	errno = EINVAL;
	601	return -1;
	602	}
	603	*offset += request.len;
	604
	605	TRACE("Read %u byte(s)", request.len);
	606
	607	if (nbd_send_reply(csock, &reply) == -1)
	608	return -1;
	609
	610	TRACE("Sending data to client");
	611
	612	if (write_sync(csock, data, request.len) != request.len) {
	613	LOG("writing to socket failed");
	614	errno = EINVAL;
	615	return -1;
	616	}
	617	break;
	618	case NBD_CMD_WRITE:
	619	TRACE("Request type is WRITE");
	620
	621	TRACE("Reading %u byte(s)", request.len);
	622
	623	if (read_sync(csock, data, request.len) != request.len) {
	624	LOG("reading from socket failed");
	625	errno = EINVAL;
	626	return -1;
	627	}
	628
	629	if (readonly) {
	630	TRACE("Server is read-only, return error");
	631	reply.error = 1;
	632	} else {
	633	TRACE("Writing to device");
	634
	635	if (bdrv_write(bs, (request.from + dev_offset) / 512,
	636	data, request.len / 512) == -1) {
	637	LOG("writing to file failed");
	638	errno = EINVAL;
	639	return -1;
	640	}
	641
	642	*offset += request.len;
	643	}
	644
	645	if (nbd_send_reply(csock, &reply) == -1)
	646	return -1;
	647	break;
	648	case NBD_CMD_DISC:
	649	TRACE("Request type is DISCONNECT");
	650	errno = 0;
	651	return 1;
	652	default:
	653	LOG("invalid request type (%u) received", request.type);
	654	errno = EINVAL;
	655	return -1;
	656	}
	657
	658	TRACE("Request/Reply complete");
	659
	660	return 0;
	661	}