[qemu.git] / nbd.c

/*
 *  Copyright (C) 2005  Anthony Liguori <[email protected]>
 *
 *  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>
#ifdef __sun__
#include <sys/ioccom.h>
#endif
#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 <[email protected]>
	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>
7e00eb9b AL	25	#ifdef __sun__
	26	#include <sys/ioccom.h>
	27	#endif
7a5ca864 FB	28	#include <ctype.h>
	29	#include <inttypes.h>
	30	#include <sys/socket.h>
cd831bd7	31	#include <sys/un.h>
7a5ca864 FB	32	#include <netinet/in.h>
	33	#include <netinet/tcp.h>
	34	#include <arpa/inet.h>
	35	#include <netdb.h>
	36
75818250	37	#if defined(QEMU_NBD)
7a5ca864	38	extern int verbose;
75818250 TS	39	#else
	40	static int verbose = 0;
	41	#endif
	42
	43	#define TRACE(msg, ...) do { \
	44	if (verbose) LOG(msg, ## __VA_ARGS__); \
	45	} while(0)
7a5ca864 FB	46
	47	#define LOG(msg, ...) do { \
	48	fprintf(stderr, "%s:%s():L%d: " msg "\n", \
	49	__FILE__, __FUNCTION__, __LINE__, ## __VA_ARGS__); \
	50	} while(0)
	51
7a5ca864 FB	52	/* This is all part of the "official" NBD API */
	53
	54	#define NBD_REQUEST_MAGIC 0x25609513
	55	#define NBD_REPLY_MAGIC 0x67446698
	56
	57	#define NBD_SET_SOCK _IO(0xab, 0)
	58	#define NBD_SET_BLKSIZE _IO(0xab, 1)
	59	#define NBD_SET_SIZE _IO(0xab, 2)
	60	#define NBD_DO_IT _IO(0xab, 3)
	61	#define NBD_CLEAR_SOCK _IO(0xab, 4)
	62	#define NBD_CLEAR_QUE _IO(0xab, 5)
	63	#define NBD_PRINT_DEBUG _IO(0xab, 6)
	64	#define NBD_SET_SIZE_BLOCKS _IO(0xab, 7)
	65	#define NBD_DISCONNECT _IO(0xab, 8)
	66
	67	/* That's all folks */
	68
75818250 TS	69	#define read_sync(fd, buffer, size) nbd_wr_sync(fd, buffer, size, true)
75818250 TS	70	#define write_sync(fd, buffer, size) nbd_wr_sync(fd, buffer, size, false)
7a5ca864	71
75818250	72	size_t nbd_wr_sync(int fd, void *buffer, size_t size, bool do_read)
7a5ca864 FB	73	{
	74	size_t offset = 0;
	75
	76	while (offset < size) {
	77	ssize_t len;
	78
	79	if (do_read) {
	80	len = read(fd, buffer + offset, size - offset);
	81	} else {
	82	len = write(fd, buffer + offset, size - offset);
	83	}
	84
	85	/* recoverable error */
75818250	86	if (len == -1 && (errno == EAGAIN \|\| errno == EINTR)) {
7a5ca864 FB	87	continue;
	88	}
	89
	90	/* eof */
	91	if (len == 0) {
	92	break;
	93	}
	94
	95	/* unrecoverable error */
	96	if (len == -1) {
	97	return 0;
	98	}
	99
	100	offset += len;
	101	}
	102
	103	return offset;
	104	}
	105
75818250	106	int tcp_socket_outgoing(const char *address, uint16_t port)
7a5ca864 FB	107	{
	108	int s;
	109	struct in_addr in;
	110	struct sockaddr_in addr;
	111	int serrno;
	112
	113	s = socket(PF_INET, SOCK_STREAM, 0);
	114	if (s == -1) {
	115	return -1;
	116	}
	117
	118	if (inet_aton(address, &in) == 0) {
	119	struct hostent *ent;
	120
	121	ent = gethostbyname(address);
	122	if (ent == NULL) {
	123	goto error;
	124	}
	125
	126	memcpy(&in, ent->h_addr, sizeof(in));
	127	}
	128
	129	addr.sin_family = AF_INET;
	130	addr.sin_port = htons(port);
	131	memcpy(&addr.sin_addr.s_addr, &in, sizeof(in));
	132
	133	if (connect(s, (struct sockaddr *)&addr, sizeof(addr)) == -1) {
	134	goto error;
	135	}
	136
	137	return s;
	138	error:
	139	serrno = errno;
	140	close(s);
	141	errno = serrno;
	142	return -1;
	143	}
	144
	145	int tcp_socket_incoming(const char *address, uint16_t port)
	146	{
	147	int s;
	148	struct in_addr in;
	149	struct sockaddr_in addr;
	150	int serrno;
	151	int opt;
	152
	153	s = socket(PF_INET, SOCK_STREAM, 0);
	154	if (s == -1) {
	155	return -1;
	156	}
	157
	158	if (inet_aton(address, &in) == 0) {
	159	struct hostent *ent;
	160
	161	ent = gethostbyname(address);
	162	if (ent == NULL) {
	163	goto error;
	164	}
	165
	166	memcpy(&in, ent->h_addr, sizeof(in));
	167	}
	168
	169	addr.sin_family = AF_INET;
	170	addr.sin_port = htons(port);
171	memcpy(&addr.sin_addr.s_addr, &in, sizeof(in));
172
173	opt = 1;
174	if (setsockopt(s, SOL_SOCKET, SO_REUSEADDR, &opt, sizeof(opt)) == -1) {
175	goto error;
176	}
177
178	if (bind(s, (struct sockaddr *)&addr, sizeof(addr)) == -1) {
179	goto error;
180	}
181
182	if (listen(s, 128) == -1) {
183	goto error;
184	}
185
186	return s;
187	error:
188	serrno = errno;
189	close(s);
190	errno = serrno;
191	return -1;
192	}
193
cd831bd7 TS	194	int unix_socket_incoming(const char *path)
	195	{
	196	int s;
	197	struct sockaddr_un addr;
	198	int serrno;
	199
	200	s = socket(PF_UNIX, SOCK_STREAM, 0);
	201	if (s == -1) {
	202	return -1;
	203	}
	204
	205	memset(&addr, 0, sizeof(addr));
	206	addr.sun_family = AF_UNIX;
	207	pstrcpy(addr.sun_path, sizeof(addr.sun_path), path);
	208
	209	if (bind(s, (struct sockaddr *)&addr, sizeof(addr)) == -1) {
	210	goto error;
	211	}
	212
	213	if (listen(s, 128) == -1) {
	214	goto error;
	215	}
	216
	217	return s;
	218	error:
	219	serrno = errno;
	220	close(s);
	221	errno = serrno;
	222	return -1;
	223	}
	224
	225	int unix_socket_outgoing(const char *path)
	226	{
	227	int s;
	228	struct sockaddr_un addr;
	229	int serrno;
	230
	231	s = socket(PF_UNIX, SOCK_STREAM, 0);
	232	if (s == -1) {
	233	return -1;
	234	}
	235
	236	memset(&addr, 0, sizeof(addr));
	237	addr.sun_family = AF_UNIX;
	238	pstrcpy(addr.sun_path, sizeof(addr.sun_path), path);
	239
	240	if (connect(s, (struct sockaddr *)&addr, sizeof(addr)) == -1) {
	241	goto error;
	242	}
	243
	244	return s;
	245	error:
	246	serrno = errno;
	247	close(s);
	248	errno = serrno;
	249	return -1;
	250	}
	251
	252
7a5ca864 FB	253	/* Basic flow
	254
	255	Server Client
	256
	257	Negotiate
	258	Request
	259	Response
	260	Request
	261	Response
	262	...
	263	...
	264	Request (type == 2)
	265	*/
	266
	267	int nbd_negotiate(BlockDriverState *bs, int csock, off_t size)
	268	{
	269	char buf[8 + 8 + 8 + 128];
	270
	271	/* Negotiate
	272	[ 0 .. 7] passwd ("NBDMAGIC")
	273	[ 8 .. 15] magic (0x00420281861253)
	274	[16 .. 23] size
	275	[24 .. 151] reserved (0)
	276	*/
	277
	278	TRACE("Beginning negotiation.");
	279	memcpy(buf, "NBDMAGIC", 8);
	280	cpu_to_be64w((uint64_t*)(buf + 8), 0x00420281861253LL);
	281	cpu_to_be64w((uint64_t*)(buf + 16), size);
	282	memset(buf + 24, 0, 128);
	283
	284	if (write_sync(csock, buf, sizeof(buf)) != sizeof(buf)) {
	285	LOG("write failed");
	286	errno = EINVAL;
	287	return -1;
	288	}
	289
	290	TRACE("Negotation succeeded.");
	291
	292	return 0;
	293	}
	294
cd831bd7	295	int nbd_receive_negotiate(int csock, off_t size, size_t blocksize)
7a5ca864 FB	296	{
	297	char buf[8 + 8 + 8 + 128];
	298	uint64_t magic;
7a5ca864 FB	299
	300	TRACE("Receiving negotation.");
	301
	302	if (read_sync(csock, buf, sizeof(buf)) != sizeof(buf)) {
	303	LOG("read failed");
	304	errno = EINVAL;
	305	return -1;
	306	}
	307
	308	magic = be64_to_cpup((uint64_t*)(buf + 8));
cd831bd7 TS	309	size = be64_to_cpup((uint64_t)(buf + 16));
cd831bd7 TS	310	*blocksize = 1024;
7a5ca864 FB	311
	312	TRACE("Magic is %c%c%c%c%c%c%c%c",
	313	isprint(buf[0]) ? buf[0] : '.',
	314	isprint(buf[1]) ? buf[1] : '.',
	315	isprint(buf[2]) ? buf[2] : '.',
	316	isprint(buf[3]) ? buf[3] : '.',
	317	isprint(buf[4]) ? buf[4] : '.',
	318	isprint(buf[5]) ? buf[5] : '.',
	319	isprint(buf[6]) ? buf[6] : '.',
	320	isprint(buf[7]) ? buf[7] : '.');
	321	TRACE("Magic is 0x%" PRIx64, magic);
cd831bd7	322	TRACE("Size is %" PRIu64, *size);
7a5ca864 FB	323
	324	if (memcmp(buf, "NBDMAGIC", 8) != 0) {
	325	LOG("Invalid magic received");
	326	errno = EINVAL;
	327	return -1;
	328	}
	329
	330	TRACE("Checking magic");
	331
	332	if (magic != 0x00420281861253LL) {
	333	LOG("Bad magic received");
	334	errno = EINVAL;
	335	return -1;
	336	}
cd831bd7 TS	337	return 0;
cd831bd7 TS	338	}
7a5ca864	339
cd831bd7 TS	340	int nbd_init(int fd, int csock, off_t size, size_t blocksize)
cd831bd7 TS	341	{
7a5ca864 FB	342	TRACE("Setting block size to %lu", (unsigned long)blocksize);
	343
	344	if (ioctl(fd, NBD_SET_BLKSIZE, blocksize) == -1) {
	345	int serrno = errno;
	346	LOG("Failed setting NBD block size");
	347	errno = serrno;
	348	return -1;
	349	}
	350
	351	TRACE("Setting size to %llu block(s)",
	352	(unsigned long long)(size / blocksize));
	353
	354	if (ioctl(fd, NBD_SET_SIZE_BLOCKS, size / blocksize) == -1) {
	355	int serrno = errno;
	356	LOG("Failed setting size (in blocks)");
	357	errno = serrno;
	358	return -1;
	359	}
	360
	361	TRACE("Clearing NBD socket");
	362
	363	if (ioctl(fd, NBD_CLEAR_SOCK) == -1) {
	364	int serrno = errno;
	365	LOG("Failed clearing NBD socket");
	366	errno = serrno;
	367	return -1;
	368	}
	369
	370	TRACE("Setting NBD socket");
	371
	372	if (ioctl(fd, NBD_SET_SOCK, csock) == -1) {
	373	int serrno = errno;
	374	LOG("Failed to set NBD socket");
	375	errno = serrno;
	376	return -1;
	377	}
	378
	379	TRACE("Negotiation ended");
	380
	381	return 0;
	382	}
	383
	384	int nbd_disconnect(int fd)
	385	{
	386	ioctl(fd, NBD_CLEAR_QUE);
	387	ioctl(fd, NBD_DISCONNECT);
	388	ioctl(fd, NBD_CLEAR_SOCK);
	389	return 0;
	390	}
	391
	392	int nbd_client(int fd, int csock)
	393	{
	394	int ret;
	395	int serrno;
	396
	397	TRACE("Doing NBD loop");
	398
	399	ret = ioctl(fd, NBD_DO_IT);
	400	serrno = errno;
	401
	402	TRACE("NBD loop returned %d: %s", ret, strerror(serrno));
	403
	404	TRACE("Clearing NBD queue");
	405	ioctl(fd, NBD_CLEAR_QUE);
406
407	TRACE("Clearing NBD socket");
408	ioctl(fd, NBD_CLEAR_SOCK);
409
410	errno = serrno;
411	return ret;
412	}
413
75818250	414	int nbd_send_request(int csock, struct nbd_request *request)
7a5ca864	415	{
7a5ca864	416	uint8_t buf[4 + 4 + 8 + 8 + 4];
7a5ca864	417
75818250 TS	418	cpu_to_be32w((uint32_t*)buf, NBD_REQUEST_MAGIC);
	419	cpu_to_be32w((uint32_t*)(buf + 4), request->type);
	420	cpu_to_be64w((uint64_t*)(buf + 8), request->handle);
	421	cpu_to_be64w((uint64_t*)(buf + 16), request->from);
	422	cpu_to_be32w((uint32_t*)(buf + 24), request->len);
	423
	424	TRACE("Sending request to client");
	425
	426	if (write_sync(csock, buf, sizeof(buf)) != sizeof(buf)) {
	427	LOG("writing to socket failed");
	428	errno = EINVAL;
	429	return -1;
	430	}
	431	return 0;
	432	}
	433
	434
	435	static int nbd_receive_request(int csock, struct nbd_request *request)
	436	{
	437	uint8_t buf[4 + 4 + 8 + 8 + 4];
	438	uint32_t magic;
7a5ca864 FB	439
	440	if (read_sync(csock, buf, sizeof(buf)) != sizeof(buf)) {
	441	LOG("read failed");
	442	errno = EINVAL;
	443	return -1;
	444	}
	445
	446	/* Request
75818250 TS	447	[ 0 .. 3] magic (NBD_REQUEST_MAGIC)
	448	[ 4 .. 7] type (0 == READ, 1 == WRITE)
	449	[ 8 .. 15] handle
	450	[16 .. 23] from
	451	[24 .. 27] len
7a5ca864 FB	452	*/
	453
	454	magic = be32_to_cpup((uint32_t*)buf);
75818250 TS	455	request->type = be32_to_cpup((uint32_t*)(buf + 4));
	456	request->handle = be64_to_cpup((uint64_t*)(buf + 8));
	457	request->from = be64_to_cpup((uint64_t*)(buf + 16));
	458	request->len = be32_to_cpup((uint32_t*)(buf + 24));
7a5ca864 FB	459
	460	TRACE("Got request: "
	461	"{ magic = 0x%x, .type = %d, from = %" PRIu64" , len = %u }",
75818250	462	magic, request->type, request->from, request->len);
7a5ca864 FB	463
	464	if (magic != NBD_REQUEST_MAGIC) {
	465	LOG("invalid magic (got 0x%x)", magic);
	466	errno = EINVAL;
	467	return -1;
	468	}
d94888e3	469	return 0;
75818250 TS	470	}
	471
	472	int nbd_receive_reply(int csock, struct nbd_reply *reply)
	473	{
	474	uint8_t buf[4 + 4 + 8];
	475	uint32_t magic;
	476
	477	memset(buf, 0xAA, sizeof(buf));
	478
	479	if (read_sync(csock, buf, sizeof(buf)) != sizeof(buf)) {
	480	LOG("read failed");
	481	errno = EINVAL;
	482	return -1;
	483	}
	484
	485	/* Reply
	486	[ 0 .. 3] magic (NBD_REPLY_MAGIC)
	487	[ 4 .. 7] error (0 == no error)
	488	[ 7 .. 15] handle
	489	*/
	490
	491	magic = be32_to_cpup((uint32_t*)buf);
	492	reply->error = be32_to_cpup((uint32_t*)(buf + 4));
	493	reply->handle = be64_to_cpup((uint64_t*)(buf + 8));
	494
	495	TRACE("Got reply: "
	496	"{ magic = 0x%x, .error = %d, handle = %" PRIu64" }",
	497	magic, reply->error, reply->handle);
	498
	499	if (magic != NBD_REPLY_MAGIC) {
	500	LOG("invalid magic (got 0x%x)", magic);
	501	errno = EINVAL;
	502	return -1;
	503	}
	504	return 0;
	505	}
	506
	507	static int nbd_send_reply(int csock, struct nbd_reply *reply)
	508	{
	509	uint8_t buf[4 + 4 + 8];
	510
	511	/* Reply
	512	[ 0 .. 3] magic (NBD_REPLY_MAGIC)
	513	[ 4 .. 7] error (0 == no error)
	514	[ 7 .. 15] handle
	515	*/
	516	cpu_to_be32w((uint32_t*)buf, NBD_REPLY_MAGIC);
	517	cpu_to_be32w((uint32_t*)(buf + 4), reply->error);
	518	cpu_to_be64w((uint64_t*)(buf + 8), reply->handle);
	519
	520	TRACE("Sending response to client");
	521
	522	if (write_sync(csock, buf, sizeof(buf)) != sizeof(buf)) {
	523	LOG("writing to socket failed");
	524	errno = EINVAL;
	525	return -1;
	526	}
	527	return 0;
	528	}
7a5ca864	529
75818250 TS	530	int nbd_trip(BlockDriverState *bs, int csock, off_t size, uint64_t dev_offset,
	531	off_t offset, bool readonly, uint8_t data, int data_size)
	532	{
	533	struct nbd_request request;
	534	struct nbd_reply reply;
	535
	536	TRACE("Reading request.");
	537
	538	if (nbd_receive_request(csock, &request) == -1)
	539	return -1;
	540
	541	if (request.len > data_size) {
2f726488	542	LOG("len (%u) is larger than max len (%u)",
75818250	543	request.len, data_size);
7a5ca864 FB	544	errno = EINVAL;
	545	return -1;
	546	}
	547
75818250	548	if ((request.from + request.len) < request.from) {
7a5ca864 FB	549	LOG("integer overflow detected! "
	550	"you're probably being attacked");
	551	errno = EINVAL;
	552	return -1;
	553	}
	554
75818250	555	if ((request.from + request.len) > size) {
7a5ca864 FB	556	LOG("From: %" PRIu64 ", Len: %u, Size: %" PRIu64
7a5ca864 FB	557	", Offset: %" PRIu64 "\n",
75818250	558	request.from, request.len, size, dev_offset);
7a5ca864 FB	559	LOG("requested operation past EOF--bad client?");
	560	errno = EINVAL;
	561	return -1;
	562	}
	563
7a5ca864 FB	564	TRACE("Decoding type");
7a5ca864 FB	565
75818250 TS	566	reply.handle = request.handle;
	567	reply.error = 0;
	568
	569	switch (request.type) {
	570	case NBD_CMD_READ:
7a5ca864 FB	571	TRACE("Request type is READ");
7a5ca864 FB	572
75818250 TS	573	if (bdrv_read(bs, (request.from + dev_offset) / 512, data,
75818250 TS	574	request.len / 512) == -1) {
7a5ca864 FB	575	LOG("reading from file failed");
	576	errno = EINVAL;
	577	return -1;
	578	}
75818250	579	*offset += request.len;
7a5ca864	580
75818250	581	TRACE("Read %u byte(s)", request.len);
7a5ca864	582
75818250	583	if (nbd_send_reply(csock, &reply) == -1)
7a5ca864	584	return -1;
7a5ca864 FB	585
	586	TRACE("Sending data to client");
	587
75818250	588	if (write_sync(csock, data, request.len) != request.len) {
7a5ca864 FB	589	LOG("writing to socket failed");
	590	errno = EINVAL;
	591	return -1;
	592	}
	593	break;
75818250	594	case NBD_CMD_WRITE:
7a5ca864 FB	595	TRACE("Request type is WRITE");
7a5ca864 FB	596
75818250	597	TRACE("Reading %u byte(s)", request.len);
7a5ca864	598
75818250	599	if (read_sync(csock, data, request.len) != request.len) {
7a5ca864 FB	600	LOG("reading from socket failed");
	601	errno = EINVAL;
	602	return -1;
	603	}
	604
	605	if (readonly) {
	606	TRACE("Server is read-only, return error");
75818250	607	reply.error = 1;
7a5ca864 FB	608	} else {
	609	TRACE("Writing to device");
	610
75818250 TS	611	if (bdrv_write(bs, (request.from + dev_offset) / 512,
75818250 TS	612	data, request.len / 512) == -1) {
7a5ca864 FB	613	LOG("writing to file failed");
	614	errno = EINVAL;
	615	return -1;
	616	}
	617
75818250	618	*offset += request.len;
7a5ca864 FB	619	}
7a5ca864 FB	620
75818250	621	if (nbd_send_reply(csock, &reply) == -1)
7a5ca864	622	return -1;
7a5ca864	623	break;
75818250	624	case NBD_CMD_DISC:
7a5ca864 FB	625	TRACE("Request type is DISCONNECT");
	626	errno = 0;
	627	return 1;
	628	default:
75818250	629	LOG("invalid request type (%u) received", request.type);
7a5ca864 FB	630	errno = EINVAL;
	631	return -1;
	632	}
	633
	634	TRACE("Request/Reply complete");
	635
	636	return 0;
	637	}