[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>
#include <sys/ioctl.h>
#include <ctype.h>
#include <inttypes.h>
#include <sys/socket.h>
#include <sys/un.h>
#include <netinet/in.h>
#include <netinet/tcp.h>
#include <arpa/inet.h>
#include <netdb.h>

#if defined(QEMU_NBD)
extern int verbose;
#else
static int verbose = 0;
#endif

#define TRACE(msg, ...) do { \
    if (verbose) LOG(msg, ## __VA_ARGS__); \
} while(0)

#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 = read(fd, buffer + offset, size - offset);
        } else {
            len = write(fd, buffer + offset, size - offset);
        }

        /* 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;
    int serrno;

    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:
    serrno = errno;
    close(s);
    errno = serrno;
    return -1;
}

int tcp_socket_incoming(const char *address, uint16_t port)
{
    int s;
    struct in_addr in;
    struct sockaddr_in addr;
    int serrno;
    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:
    serrno = errno;
    close(s);
    errno = serrno;
    return -1;
}

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

    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:
    serrno = errno;
    close(s);
    errno = serrno;
    return -1;
}

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

    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:
    serrno = errno;
    close(s);
    errno = serrno;
    return -1;
}


/* Basic flow

   Server         Client

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

int nbd_negotiate(BlockDriverState *bs, 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",
	      isprint(buf[0]) ? buf[0] : '.',
	      isprint(buf[1]) ? buf[1] : '.',
	      isprint(buf[2]) ? buf[2] : '.',
	      isprint(buf[3]) ? buf[3] : '.',
	      isprint(buf[4]) ? buf[4] : '.',
	      isprint(buf[5]) ? buf[5] : '.',
	      isprint(buf[6]) ? buf[6] : '.',
	      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;
}

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;
}

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
75818250	1	/*
7a5ca864 FB	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
75818250	18	*/
7a5ca864 FB	19
	20	#include "nbd.h"
	21
	22	#include <errno.h>
	23	#include <string.h>
	24	#include <sys/ioctl.h>
	25	#include <ctype.h>
	26	#include <inttypes.h>
	27	#include <sys/socket.h>
cd831bd7	28	#include <sys/un.h>
7a5ca864 FB	29	#include <netinet/in.h>
	30	#include <netinet/tcp.h>
	31	#include <arpa/inet.h>
	32	#include <netdb.h>
	33
75818250	34	#if defined(QEMU_NBD)
7a5ca864	35	extern int verbose;
75818250 TS	36	#else
	37	static int verbose = 0;
	38	#endif
	39
	40	#define TRACE(msg, ...) do { \
	41	if (verbose) LOG(msg, ## __VA_ARGS__); \
	42	} while(0)
7a5ca864 FB	43
	44	#define LOG(msg, ...) do { \
	45	fprintf(stderr, "%s:%s():L%d: " msg "\n", \
	46	__FILE__, __FUNCTION__, __LINE__, ## __VA_ARGS__); \
	47	} while(0)
	48
7a5ca864 FB	49	/* This is all part of the "official" NBD API */
	50
	51	#define NBD_REQUEST_MAGIC 0x25609513
	52	#define NBD_REPLY_MAGIC 0x67446698
	53
	54	#define NBD_SET_SOCK _IO(0xab, 0)
	55	#define NBD_SET_BLKSIZE _IO(0xab, 1)
	56	#define NBD_SET_SIZE _IO(0xab, 2)
	57	#define NBD_DO_IT _IO(0xab, 3)
	58	#define NBD_CLEAR_SOCK _IO(0xab, 4)
	59	#define NBD_CLEAR_QUE _IO(0xab, 5)
	60	#define NBD_PRINT_DEBUG _IO(0xab, 6)
	61	#define NBD_SET_SIZE_BLOCKS _IO(0xab, 7)
	62	#define NBD_DISCONNECT _IO(0xab, 8)
	63
	64	/* That's all folks */
	65
75818250 TS	66	#define read_sync(fd, buffer, size) nbd_wr_sync(fd, buffer, size, true)
75818250 TS	67	#define write_sync(fd, buffer, size) nbd_wr_sync(fd, buffer, size, false)
7a5ca864	68
75818250	69	size_t nbd_wr_sync(int fd, void *buffer, size_t size, bool do_read)
7a5ca864 FB	70	{
	71	size_t offset = 0;
	72
	73	while (offset < size) {
	74	ssize_t len;
	75
	76	if (do_read) {
	77	len = read(fd, buffer + offset, size - offset);
	78	} else {
	79	len = write(fd, buffer + offset, size - offset);
	80	}
	81
	82	/* recoverable error */
75818250	83	if (len == -1 && (errno == EAGAIN \|\| errno == EINTR)) {
7a5ca864 FB	84	continue;
	85	}
	86
	87	/* eof */
	88	if (len == 0) {
	89	break;
	90	}
	91
	92	/* unrecoverable error */
	93	if (len == -1) {
	94	return 0;
	95	}
	96
	97	offset += len;
	98	}
	99
	100	return offset;
	101	}
	102
75818250	103	int tcp_socket_outgoing(const char *address, uint16_t port)
7a5ca864 FB	104	{
	105	int s;
	106	struct in_addr in;
	107	struct sockaddr_in addr;
	108	int serrno;
	109
	110	s = socket(PF_INET, SOCK_STREAM, 0);
	111	if (s == -1) {
	112	return -1;
	113	}
	114
	115	if (inet_aton(address, &in) == 0) {
	116	struct hostent *ent;
	117
	118	ent = gethostbyname(address);
	119	if (ent == NULL) {
	120	goto error;
	121	}
	122
	123	memcpy(&in, ent->h_addr, sizeof(in));
	124	}
	125
	126	addr.sin_family = AF_INET;
	127	addr.sin_port = htons(port);
	128	memcpy(&addr.sin_addr.s_addr, &in, sizeof(in));
	129
	130	if (connect(s, (struct sockaddr *)&addr, sizeof(addr)) == -1) {
	131	goto error;
	132	}
	133
	134	return s;
	135	error:
	136	serrno = errno;
	137	close(s);
	138	errno = serrno;
	139	return -1;
	140	}
	141
	142	int tcp_socket_incoming(const char *address, uint16_t port)
	143	{
	144	int s;
	145	struct in_addr in;
	146	struct sockaddr_in addr;
	147	int serrno;
	148	int opt;
	149
	150	s = socket(PF_INET, SOCK_STREAM, 0);
	151	if (s == -1) {
	152	return -1;
	153	}
	154
	155	if (inet_aton(address, &in) == 0) {
	156	struct hostent *ent;
	157
	158	ent = gethostbyname(address);
	159	if (ent == NULL) {
	160	goto error;
	161	}
	162
	163	memcpy(&in, ent->h_addr, sizeof(in));
	164	}
	165
	166	addr.sin_family = AF_INET;
	167	addr.sin_port = htons(port);
168	memcpy(&addr.sin_addr.s_addr, &in, sizeof(in));
169
170	opt = 1;
171	if (setsockopt(s, SOL_SOCKET, SO_REUSEADDR, &opt, sizeof(opt)) == -1) {
172	goto error;
173	}
174
175	if (bind(s, (struct sockaddr *)&addr, sizeof(addr)) == -1) {
176	goto error;
177	}
178
179	if (listen(s, 128) == -1) {
180	goto error;
181	}
182
183	return s;
184	error:
185	serrno = errno;
186	close(s);
187	errno = serrno;
188	return -1;
189	}
190
cd831bd7 TS	191	int unix_socket_incoming(const char *path)
	192	{
	193	int s;
	194	struct sockaddr_un addr;
	195	int serrno;
	196
	197	s = socket(PF_UNIX, SOCK_STREAM, 0);
	198	if (s == -1) {
	199	return -1;
	200	}
	201
	202	memset(&addr, 0, sizeof(addr));
	203	addr.sun_family = AF_UNIX;
	204	pstrcpy(addr.sun_path, sizeof(addr.sun_path), path);
	205
	206	if (bind(s, (struct sockaddr *)&addr, sizeof(addr)) == -1) {
	207	goto error;
	208	}
	209
	210	if (listen(s, 128) == -1) {
	211	goto error;
	212	}
	213
	214	return s;
	215	error:
	216	serrno = errno;
	217	close(s);
	218	errno = serrno;
	219	return -1;
	220	}
	221
	222	int unix_socket_outgoing(const char *path)
	223	{
	224	int s;
	225	struct sockaddr_un addr;
	226	int serrno;
	227
	228	s = socket(PF_UNIX, SOCK_STREAM, 0);
	229	if (s == -1) {
	230	return -1;
	231	}
	232
	233	memset(&addr, 0, sizeof(addr));
	234	addr.sun_family = AF_UNIX;
	235	pstrcpy(addr.sun_path, sizeof(addr.sun_path), path);
	236
	237	if (connect(s, (struct sockaddr *)&addr, sizeof(addr)) == -1) {
	238	goto error;
	239	}
	240
	241	return s;
	242	error:
	243	serrno = errno;
	244	close(s);
	245	errno = serrno;
	246	return -1;
	247	}
	248
	249
7a5ca864 FB	250	/* Basic flow
	251
	252	Server Client
	253
	254	Negotiate
	255	Request
	256	Response
	257	Request
	258	Response
	259	...
	260	...
	261	Request (type == 2)
	262	*/
	263
	264	int nbd_negotiate(BlockDriverState *bs, int csock, off_t size)
	265	{
	266	char buf[8 + 8 + 8 + 128];
	267
	268	/* Negotiate
	269	[ 0 .. 7] passwd ("NBDMAGIC")
	270	[ 8 .. 15] magic (0x00420281861253)
	271	[16 .. 23] size
	272	[24 .. 151] reserved (0)
	273	*/
	274
	275	TRACE("Beginning negotiation.");
	276	memcpy(buf, "NBDMAGIC", 8);
	277	cpu_to_be64w((uint64_t*)(buf + 8), 0x00420281861253LL);
	278	cpu_to_be64w((uint64_t*)(buf + 16), size);
	279	memset(buf + 24, 0, 128);
	280
	281	if (write_sync(csock, buf, sizeof(buf)) != sizeof(buf)) {
	282	LOG("write failed");
	283	errno = EINVAL;
	284	return -1;
	285	}
	286
	287	TRACE("Negotation succeeded.");
	288
	289	return 0;
	290	}
	291
cd831bd7	292	int nbd_receive_negotiate(int csock, off_t size, size_t blocksize)
7a5ca864 FB	293	{
	294	char buf[8 + 8 + 8 + 128];
	295	uint64_t magic;
7a5ca864 FB	296
	297	TRACE("Receiving negotation.");
	298
	299	if (read_sync(csock, buf, sizeof(buf)) != sizeof(buf)) {
	300	LOG("read failed");
	301	errno = EINVAL;
	302	return -1;
	303	}
	304
	305	magic = be64_to_cpup((uint64_t*)(buf + 8));
cd831bd7 TS	306	size = be64_to_cpup((uint64_t)(buf + 16));
cd831bd7 TS	307	*blocksize = 1024;
7a5ca864 FB	308
	309	TRACE("Magic is %c%c%c%c%c%c%c%c",
	310	isprint(buf[0]) ? buf[0] : '.',
	311	isprint(buf[1]) ? buf[1] : '.',
	312	isprint(buf[2]) ? buf[2] : '.',
	313	isprint(buf[3]) ? buf[3] : '.',
	314	isprint(buf[4]) ? buf[4] : '.',
	315	isprint(buf[5]) ? buf[5] : '.',
	316	isprint(buf[6]) ? buf[6] : '.',
	317	isprint(buf[7]) ? buf[7] : '.');
	318	TRACE("Magic is 0x%" PRIx64, magic);
cd831bd7	319	TRACE("Size is %" PRIu64, *size);
7a5ca864 FB	320
	321	if (memcmp(buf, "NBDMAGIC", 8) != 0) {
	322	LOG("Invalid magic received");
	323	errno = EINVAL;
	324	return -1;
	325	}
	326
	327	TRACE("Checking magic");
	328
	329	if (magic != 0x00420281861253LL) {
	330	LOG("Bad magic received");
	331	errno = EINVAL;
	332	return -1;
	333	}
cd831bd7 TS	334	return 0;
cd831bd7 TS	335	}
7a5ca864	336
cd831bd7 TS	337	int nbd_init(int fd, int csock, off_t size, size_t blocksize)
cd831bd7 TS	338	{
7a5ca864 FB	339	TRACE("Setting block size to %lu", (unsigned long)blocksize);
	340
	341	if (ioctl(fd, NBD_SET_BLKSIZE, blocksize) == -1) {
	342	int serrno = errno;
	343	LOG("Failed setting NBD block size");
	344	errno = serrno;
	345	return -1;
	346	}
	347
	348	TRACE("Setting size to %llu block(s)",
	349	(unsigned long long)(size / blocksize));
	350
	351	if (ioctl(fd, NBD_SET_SIZE_BLOCKS, size / blocksize) == -1) {
	352	int serrno = errno;
	353	LOG("Failed setting size (in blocks)");
	354	errno = serrno;
	355	return -1;
	356	}
	357
	358	TRACE("Clearing NBD socket");
	359
	360	if (ioctl(fd, NBD_CLEAR_SOCK) == -1) {
	361	int serrno = errno;
	362	LOG("Failed clearing NBD socket");
	363	errno = serrno;
	364	return -1;
	365	}
	366
	367	TRACE("Setting NBD socket");
	368
	369	if (ioctl(fd, NBD_SET_SOCK, csock) == -1) {
	370	int serrno = errno;
	371	LOG("Failed to set NBD socket");
	372	errno = serrno;
	373	return -1;
	374	}
	375
	376	TRACE("Negotiation ended");
	377
	378	return 0;
	379	}
	380
	381	int nbd_disconnect(int fd)
	382	{
	383	ioctl(fd, NBD_CLEAR_QUE);
	384	ioctl(fd, NBD_DISCONNECT);
	385	ioctl(fd, NBD_CLEAR_SOCK);
	386	return 0;
	387	}
	388
	389	int nbd_client(int fd, int csock)
	390	{
	391	int ret;
	392	int serrno;
	393
	394	TRACE("Doing NBD loop");
	395
	396	ret = ioctl(fd, NBD_DO_IT);
	397	serrno = errno;
	398
	399	TRACE("NBD loop returned %d: %s", ret, strerror(serrno));
	400
	401	TRACE("Clearing NBD queue");
	402	ioctl(fd, NBD_CLEAR_QUE);
403
404	TRACE("Clearing NBD socket");
405	ioctl(fd, NBD_CLEAR_SOCK);
406
407	errno = serrno;
408	return ret;
409	}
410
75818250	411	int nbd_send_request(int csock, struct nbd_request *request)
7a5ca864	412	{
7a5ca864	413	uint8_t buf[4 + 4 + 8 + 8 + 4];
7a5ca864	414
75818250 TS	415	cpu_to_be32w((uint32_t*)buf, NBD_REQUEST_MAGIC);
	416	cpu_to_be32w((uint32_t*)(buf + 4), request->type);
	417	cpu_to_be64w((uint64_t*)(buf + 8), request->handle);
	418	cpu_to_be64w((uint64_t*)(buf + 16), request->from);
	419	cpu_to_be32w((uint32_t*)(buf + 24), request->len);
	420
	421	TRACE("Sending request to client");
	422
	423	if (write_sync(csock, buf, sizeof(buf)) != sizeof(buf)) {
	424	LOG("writing to socket failed");
	425	errno = EINVAL;
	426	return -1;
	427	}
	428	return 0;
	429	}
	430
	431
	432	static int nbd_receive_request(int csock, struct nbd_request *request)
	433	{
	434	uint8_t buf[4 + 4 + 8 + 8 + 4];
	435	uint32_t magic;
7a5ca864 FB	436
	437	if (read_sync(csock, buf, sizeof(buf)) != sizeof(buf)) {
	438	LOG("read failed");
	439	errno = EINVAL;
	440	return -1;
	441	}
	442
	443	/* Request
75818250 TS	444	[ 0 .. 3] magic (NBD_REQUEST_MAGIC)
	445	[ 4 .. 7] type (0 == READ, 1 == WRITE)
	446	[ 8 .. 15] handle
	447	[16 .. 23] from
	448	[24 .. 27] len
7a5ca864 FB	449	*/
	450
	451	magic = be32_to_cpup((uint32_t*)buf);
75818250 TS	452	request->type = be32_to_cpup((uint32_t*)(buf + 4));
	453	request->handle = be64_to_cpup((uint64_t*)(buf + 8));
	454	request->from = be64_to_cpup((uint64_t*)(buf + 16));
	455	request->len = be32_to_cpup((uint32_t*)(buf + 24));
7a5ca864 FB	456
	457	TRACE("Got request: "
	458	"{ magic = 0x%x, .type = %d, from = %" PRIu64" , len = %u }",
75818250	459	magic, request->type, request->from, request->len);
7a5ca864 FB	460
	461	if (magic != NBD_REQUEST_MAGIC) {
	462	LOG("invalid magic (got 0x%x)", magic);
	463	errno = EINVAL;
	464	return -1;
	465	}
d94888e3	466	return 0;
75818250 TS	467	}
	468
	469	int nbd_receive_reply(int csock, struct nbd_reply *reply)
	470	{
	471	uint8_t buf[4 + 4 + 8];
	472	uint32_t magic;
	473
	474	memset(buf, 0xAA, sizeof(buf));
	475
	476	if (read_sync(csock, buf, sizeof(buf)) != sizeof(buf)) {
	477	LOG("read failed");
	478	errno = EINVAL;
	479	return -1;
	480	}
	481
	482	/* Reply
	483	[ 0 .. 3] magic (NBD_REPLY_MAGIC)
	484	[ 4 .. 7] error (0 == no error)
	485	[ 7 .. 15] handle
	486	*/
	487
	488	magic = be32_to_cpup((uint32_t*)buf);
	489	reply->error = be32_to_cpup((uint32_t*)(buf + 4));
	490	reply->handle = be64_to_cpup((uint64_t*)(buf + 8));
	491
	492	TRACE("Got reply: "
	493	"{ magic = 0x%x, .error = %d, handle = %" PRIu64" }",
	494	magic, reply->error, reply->handle);
	495
	496	if (magic != NBD_REPLY_MAGIC) {
	497	LOG("invalid magic (got 0x%x)", magic);
	498	errno = EINVAL;
	499	return -1;
	500	}
	501	return 0;
	502	}
	503
	504	static int nbd_send_reply(int csock, struct nbd_reply *reply)
	505	{
	506	uint8_t buf[4 + 4 + 8];
	507
	508	/* Reply
	509	[ 0 .. 3] magic (NBD_REPLY_MAGIC)
	510	[ 4 .. 7] error (0 == no error)
	511	[ 7 .. 15] handle
	512	*/
	513	cpu_to_be32w((uint32_t*)buf, NBD_REPLY_MAGIC);
	514	cpu_to_be32w((uint32_t*)(buf + 4), reply->error);
	515	cpu_to_be64w((uint64_t*)(buf + 8), reply->handle);
	516
	517	TRACE("Sending response to client");
	518
	519	if (write_sync(csock, buf, sizeof(buf)) != sizeof(buf)) {
	520	LOG("writing to socket failed");
	521	errno = EINVAL;
	522	return -1;
	523	}
	524	return 0;
	525	}
7a5ca864	526
75818250 TS	527	int nbd_trip(BlockDriverState *bs, int csock, off_t size, uint64_t dev_offset,
	528	off_t offset, bool readonly, uint8_t data, int data_size)
	529	{
	530	struct nbd_request request;
	531	struct nbd_reply reply;
	532
	533	TRACE("Reading request.");
	534
	535	if (nbd_receive_request(csock, &request) == -1)
	536	return -1;
	537
	538	if (request.len > data_size) {
2f726488	539	LOG("len (%u) is larger than max len (%u)",
75818250	540	request.len, data_size);
7a5ca864 FB	541	errno = EINVAL;
	542	return -1;
	543	}
	544
75818250	545	if ((request.from + request.len) < request.from) {
7a5ca864 FB	546	LOG("integer overflow detected! "
	547	"you're probably being attacked");
	548	errno = EINVAL;
	549	return -1;
	550	}
	551
75818250	552	if ((request.from + request.len) > size) {
7a5ca864 FB	553	LOG("From: %" PRIu64 ", Len: %u, Size: %" PRIu64
7a5ca864 FB	554	", Offset: %" PRIu64 "\n",
75818250	555	request.from, request.len, size, dev_offset);
7a5ca864 FB	556	LOG("requested operation past EOF--bad client?");
	557	errno = EINVAL;
	558	return -1;
	559	}
	560
7a5ca864 FB	561	TRACE("Decoding type");
7a5ca864 FB	562
75818250 TS	563	reply.handle = request.handle;
	564	reply.error = 0;
	565
	566	switch (request.type) {
	567	case NBD_CMD_READ:
7a5ca864 FB	568	TRACE("Request type is READ");
7a5ca864 FB	569
75818250 TS	570	if (bdrv_read(bs, (request.from + dev_offset) / 512, data,
75818250 TS	571	request.len / 512) == -1) {
7a5ca864 FB	572	LOG("reading from file failed");
	573	errno = EINVAL;
	574	return -1;
	575	}
75818250	576	*offset += request.len;
7a5ca864	577
75818250	578	TRACE("Read %u byte(s)", request.len);
7a5ca864	579
75818250	580	if (nbd_send_reply(csock, &reply) == -1)
7a5ca864	581	return -1;
7a5ca864 FB	582
	583	TRACE("Sending data to client");
	584
75818250	585	if (write_sync(csock, data, request.len) != request.len) {
7a5ca864 FB	586	LOG("writing to socket failed");
	587	errno = EINVAL;
	588	return -1;
	589	}
	590	break;
75818250	591	case NBD_CMD_WRITE:
7a5ca864 FB	592	TRACE("Request type is WRITE");
7a5ca864 FB	593
75818250	594	TRACE("Reading %u byte(s)", request.len);
7a5ca864	595
75818250	596	if (read_sync(csock, data, request.len) != request.len) {
7a5ca864 FB	597	LOG("reading from socket failed");
	598	errno = EINVAL;
	599	return -1;
	600	}
	601
	602	if (readonly) {
	603	TRACE("Server is read-only, return error");
75818250	604	reply.error = 1;
7a5ca864 FB	605	} else {
	606	TRACE("Writing to device");
	607
75818250 TS	608	if (bdrv_write(bs, (request.from + dev_offset) / 512,
75818250 TS	609	data, request.len / 512) == -1) {
7a5ca864 FB	610	LOG("writing to file failed");
	611	errno = EINVAL;
	612	return -1;
	613	}
	614
75818250	615	*offset += request.len;
7a5ca864 FB	616	}
7a5ca864 FB	617
75818250	618	if (nbd_send_reply(csock, &reply) == -1)
7a5ca864	619	return -1;
7a5ca864	620	break;
75818250	621	case NBD_CMD_DISC:
7a5ca864 FB	622	TRACE("Request type is DISCONNECT");
	623	errno = 0;
	624	return 1;
	625	default:
75818250	626	LOG("invalid request type (%u) received", request.type);
7a5ca864 FB	627	errno = EINVAL;
	628	return -1;
	629	}
	630
	631	TRACE("Request/Reply complete");
	632
	633	return 0;
	634	}