[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, see <http://www.gnu.org/licenses/>.
 */

#include "nbd.h"
#include "block.h"

#include <errno.h>
#include <string.h>
#ifndef _WIN32
#include <sys/ioctl.h>
#endif
#if defined(__sun__) || defined(__HAIKU__)
#include <sys/ioccom.h>
#endif
#include <ctype.h>
#include <inttypes.h>

#ifdef __linux__
#include <linux/fs.h>
#endif

#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_REPLY_SIZE          (4 + 4 + 8)
#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)
#define NBD_SET_TIMEOUT         _IO(0xab, 9)
#define NBD_SET_FLAGS           _IO(0xab, 10)

#define NBD_OPT_EXPORT_NAME     (1 << 0)

/* 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;

    if (qemu_in_coroutine()) {
        if (do_read) {
            return qemu_co_recv(fd, buffer, size);
        } else {
            return qemu_co_send(fd, buffer, size);
        }
    }

    while (offset < size) {
        ssize_t len;

        if (do_read) {
            len = qemu_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;
}

static void combine_addr(char *buf, size_t len, const char* address,
                         uint16_t port)
{
    /* If the address-part contains a colon, it's an IPv6 IP so needs [] */
    if (strstr(address, ":")) {
        snprintf(buf, len, "[%s]:%u", address, port);
    } else {
        snprintf(buf, len, "%s:%u", address, port);
    }
}

int tcp_socket_outgoing(const char *address, uint16_t port)
{
    char address_and_port[128];
    combine_addr(address_and_port, 128, address, port);
    return tcp_socket_outgoing_spec(address_and_port);
}

int tcp_socket_outgoing_spec(const char *address_and_port)
{
    return inet_connect(address_and_port, SOCK_STREAM);
}

int tcp_socket_incoming(const char *address, uint16_t port)
{
    char address_and_port[128];
    combine_addr(address_and_port, 128, address, port);
    return tcp_socket_incoming_spec(address_and_port);
}

int tcp_socket_incoming_spec(const char *address_and_port)
{
    char *ostr  = NULL;
    int olen = 0;
    return inet_listen(address_and_port, ostr, olen, SOCK_STREAM, 0);
}

int unix_socket_incoming(const char *path)
{
    char *ostr = NULL;
    int olen = 0;

    return unix_listen(path, ostr, olen);
}

int unix_socket_outgoing(const char *path)
{
    return unix_connect(path);
}

/* Basic flow

   Server         Client

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

int nbd_negotiate(int csock, off_t size, uint32_t flags)
{
    char buf[8 + 8 + 8 + 128];

    /* Negotiate
        [ 0 ..   7]   passwd   ("NBDMAGIC")
        [ 8 ..  15]   magic    (0x00420281861253)
        [16 ..  23]   size
        [24 ..  27]   flags
        [28 .. 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);
    cpu_to_be32w((uint32_t*)(buf + 24),
                 flags | NBD_FLAG_HAS_FLAGS | NBD_FLAG_SEND_TRIM |
                 NBD_FLAG_SEND_FLUSH | NBD_FLAG_SEND_FUA);
    memset(buf + 28, 0, 124);

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

    TRACE("Negotiation succeeded.");

    return 0;
}

int nbd_receive_negotiate(int csock, const char *name, uint32_t *flags,
                          off_t *size, size_t *blocksize)
{
    char buf[256];
    uint64_t magic, s;
    uint16_t tmp;

    TRACE("Receiving negotiation.");

    if (read_sync(csock, buf, 8) != 8) {
        LOG("read failed");
        errno = EINVAL;
        return -1;
    }

    buf[8] = '\0';
    if (strlen(buf) == 0) {
        LOG("server connection closed");
        errno = EINVAL;
        return -1;
    }

    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] : '.');

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

    if (read_sync(csock, &magic, sizeof(magic)) != sizeof(magic)) {
        LOG("read failed");
        errno = EINVAL;
        return -1;
    }
    magic = be64_to_cpu(magic);
    TRACE("Magic is 0x%" PRIx64, magic);

    if (name) {
        uint32_t reserved = 0;
        uint32_t opt;
        uint32_t namesize;

        TRACE("Checking magic (opts_magic)");
        if (magic != 0x49484156454F5054LL) {
            LOG("Bad magic received");
            errno = EINVAL;
            return -1;
        }
        if (read_sync(csock, &tmp, sizeof(tmp)) != sizeof(tmp)) {
            LOG("flags read failed");
            errno = EINVAL;
            return -1;
        }
        *flags = be16_to_cpu(tmp) << 16;
        /* reserved for future use */
        if (write_sync(csock, &reserved, sizeof(reserved)) !=
            sizeof(reserved)) {
            LOG("write failed (reserved)");
            errno = EINVAL;
            return -1;
        }
        /* write the export name */
        magic = cpu_to_be64(magic);
        if (write_sync(csock, &magic, sizeof(magic)) != sizeof(magic)) {
            LOG("write failed (magic)");
            errno = EINVAL;
            return -1;
        }
        opt = cpu_to_be32(NBD_OPT_EXPORT_NAME);
        if (write_sync(csock, &opt, sizeof(opt)) != sizeof(opt)) {
            LOG("write failed (opt)");
            errno = EINVAL;
            return -1;
        }
        namesize = cpu_to_be32(strlen(name));
        if (write_sync(csock, &namesize, sizeof(namesize)) !=
            sizeof(namesize)) {
            LOG("write failed (namesize)");
            errno = EINVAL;
            return -1;
        }
        if (write_sync(csock, (char*)name, strlen(name)) != strlen(name)) {
            LOG("write failed (name)");
            errno = EINVAL;
            return -1;
        }
    } else {
        TRACE("Checking magic (cli_magic)");

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

    if (read_sync(csock, &s, sizeof(s)) != sizeof(s)) {
        LOG("read failed");
        errno = EINVAL;
        return -1;
    }
    *size = be64_to_cpu(s);
    *blocksize = 1024;
    TRACE("Size is %" PRIu64, *size);

    if (!name) {
        if (read_sync(csock, flags, sizeof(*flags)) != sizeof(*flags)) {
            LOG("read failed (flags)");
            errno = EINVAL;
            return -1;
        }
        *flags = be32_to_cpup(flags);
    } else {
        if (read_sync(csock, &tmp, sizeof(tmp)) != sizeof(tmp)) {
            LOG("read failed (tmp)");
            errno = EINVAL;
            return -1;
        }
        *flags |= be32_to_cpu(tmp);
    }
    if (read_sync(csock, &buf, 124) != 124) {
        LOG("read failed (buf)");
        errno = EINVAL;
        return -1;
    }
        return 0;
}

#ifdef __linux__
int nbd_init(int fd, int csock, uint32_t flags, off_t size, size_t blocksize)
{
    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("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 %zd block(s)", (size_t)(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;
    }

    if (flags & NBD_FLAG_READ_ONLY) {
        int read_only = 1;
        TRACE("Setting readonly attribute");

        if (ioctl(fd, BLKROSET, (unsigned long) &read_only) < 0) {
            int serrno = errno;
            LOG("Failed setting read-only attribute");
            errno = serrno;
            return -1;
        }
    }

    if (ioctl(fd, NBD_SET_FLAGS, flags) < 0
        && errno != ENOTTY) {
        int serrno = errno;
        LOG("Failed setting flags");
        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 ret;
    int serrno;

    TRACE("Doing NBD loop");

    ret = ioctl(fd, NBD_DO_IT);
    if (ret == -1 && errno == EPIPE) {
        /* NBD_DO_IT normally returns EPIPE when someone has disconnected
         * the socket via NBD_DISCONNECT.  We do not want to return 1 in
         * that case.
         */
        ret = 0;
    }
    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, uint32_t flags, off_t size, size_t blocksize)
{
    errno = ENOTSUP;
    return -1;
}

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

int nbd_client(int fd)
{
    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: "
          "{ .from = %" PRIu64", .len = %u, .handle = %" PRIu64", .type=%i}",
          request->from, request->len, request->handle, request->type);

    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[NBD_REPLY_SIZE];
    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, uint32_t nbdflags,
             uint8_t *data)
{
    struct nbd_request request;
    struct nbd_reply reply;
    int ret;

    TRACE("Reading request.");

    if (nbd_receive_request(csock, &request) == -1)
        return -1;

    if (request.len + NBD_REPLY_SIZE > NBD_BUFFER_SIZE) {
        LOG("len (%u) is larger than max len (%u)",
            request.len + NBD_REPLY_SIZE, NBD_BUFFER_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 & NBD_CMD_MASK_COMMAND) {
    case NBD_CMD_READ:
        TRACE("Request type is READ");

        ret = bdrv_read(bs, (request.from + dev_offset) / 512,
                        data + NBD_REPLY_SIZE,
                        request.len / 512);
        if (ret < 0) {
            LOG("reading from file failed");
            reply.error = -ret;
            request.len = 0;
        }

        TRACE("Read %u byte(s)", request.len);

        /* Reply
           [ 0 ..  3]    magic   (NBD_REPLY_MAGIC)
           [ 4 ..  7]    error   (0 == no error)
           [ 7 .. 15]    handle
         */

        cpu_to_be32w((uint32_t*)data, NBD_REPLY_MAGIC);
        cpu_to_be32w((uint32_t*)(data + 4), reply.error);
        cpu_to_be64w((uint64_t*)(data + 8), reply.handle);

        TRACE("Sending data to client");

        if (write_sync(csock, data,
                   request.len + NBD_REPLY_SIZE) !=
                   request.len + NBD_REPLY_SIZE) {
            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 (nbdflags & NBD_FLAG_READ_ONLY) {
            TRACE("Server is read-only, return error");
            reply.error = 1;
        } else {
            TRACE("Writing to device");

            ret = bdrv_write(bs, (request.from + dev_offset) / 512,
                             data, request.len / 512);
            if (ret < 0) {
                LOG("writing to file failed");
                reply.error = -ret;
                request.len = 0;
            }

            if (request.type & NBD_CMD_FLAG_FUA) {
                ret = bdrv_flush(bs);
                if (ret < 0) {
                    LOG("flush failed");
                    reply.error = -ret;
                }
            }
        }

        if (nbd_send_reply(csock, &reply) == -1)
            return -1;
        break;
    case NBD_CMD_DISC:
        TRACE("Request type is DISCONNECT");
        errno = 0;
        return 1;
    case NBD_CMD_FLUSH:
        TRACE("Request type is FLUSH");

        ret = bdrv_flush(bs);
        if (ret < 0) {
            LOG("flush failed");
            reply.error = -ret;
        }

        if (nbd_send_reply(csock, &reply) == -1)
            return -1;
        break;
    case NBD_CMD_TRIM:
        TRACE("Request type is TRIM");
        ret = bdrv_discard(bs, (request.from + dev_offset) / 512,
                           request.len / 512);
        if (ret < 0) {
            LOG("discard failed");
            reply.error = -ret;
        }
        if (nbd_send_reply(csock, &reply) == -1)
            return -1;
        break;
    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
8167ee88	16	* along with this program; if not, see <http://www.gnu.org/licenses/>.
75818250	17	*/
7a5ca864 FB	18
7a5ca864 FB	19	#include "nbd.h"
ab359cd1	20	#include "block.h"
7a5ca864 FB	21
	22	#include <errno.h>
	23	#include <string.h>
03ff3ca3	24	#ifndef _WIN32
7a5ca864	25	#include <sys/ioctl.h>
03ff3ca3	26	#endif
5dc2eec9	27	#if defined(__sun__) \|\| defined(__HAIKU__)
7e00eb9b AL	28	#include <sys/ioccom.h>
7e00eb9b AL	29	#endif
7a5ca864 FB	30	#include <ctype.h>
7a5ca864 FB	31	#include <inttypes.h>
75818250	32
b90fb4b8 PB	33	#ifdef __linux__
	34	#include <linux/fs.h>
	35	#endif
	36
03ff3ca3 AL	37	#include "qemu_socket.h"
	38
	39	//#define DEBUG_NBD
	40
	41	#ifdef DEBUG_NBD
75818250	42	#define TRACE(msg, ...) do { \
03ff3ca3	43	LOG(msg, ## __VA_ARGS__); \
75818250	44	} while(0)
03ff3ca3 AL	45	#else
	46	#define TRACE(msg, ...) \
	47	do { } while (0)
	48	#endif
7a5ca864 FB	49
	50	#define LOG(msg, ...) do { \
	51	fprintf(stderr, "%s:%s():L%d: " msg "\n", \
	52	__FILE__, __FUNCTION__, __LINE__, ## __VA_ARGS__); \
	53	} while(0)
	54
7a5ca864 FB	55	/* This is all part of the "official" NBD API */
7a5ca864 FB	56
b2e3d87f	57	#define NBD_REPLY_SIZE (4 + 4 + 8)
7a5ca864 FB	58	#define NBD_REQUEST_MAGIC 0x25609513
	59	#define NBD_REPLY_MAGIC 0x67446698
	60
	61	#define NBD_SET_SOCK _IO(0xab, 0)
	62	#define NBD_SET_BLKSIZE _IO(0xab, 1)
	63	#define NBD_SET_SIZE _IO(0xab, 2)
	64	#define NBD_DO_IT _IO(0xab, 3)
	65	#define NBD_CLEAR_SOCK _IO(0xab, 4)
	66	#define NBD_CLEAR_QUE _IO(0xab, 5)
b2e3d87f NT	67	#define NBD_PRINT_DEBUG _IO(0xab, 6)
b2e3d87f NT	68	#define NBD_SET_SIZE_BLOCKS _IO(0xab, 7)
7a5ca864	69	#define NBD_DISCONNECT _IO(0xab, 8)
bbb74edd PB	70	#define NBD_SET_TIMEOUT _IO(0xab, 9)
bbb74edd PB	71	#define NBD_SET_FLAGS _IO(0xab, 10)
7a5ca864	72
b2e3d87f	73	#define NBD_OPT_EXPORT_NAME (1 << 0)
1d45f8b5	74
7a5ca864 FB	75	/* That's all folks */
7a5ca864 FB	76
75818250 TS	77	#define read_sync(fd, buffer, size) nbd_wr_sync(fd, buffer, size, true)
75818250 TS	78	#define write_sync(fd, buffer, size) nbd_wr_sync(fd, buffer, size, false)
7a5ca864	79
75818250	80	size_t nbd_wr_sync(int fd, void *buffer, size_t size, bool do_read)
7a5ca864 FB	81	{
	82	size_t offset = 0;
	83
ae255e52 PB	84	if (qemu_in_coroutine()) {
	85	if (do_read) {
	86	return qemu_co_recv(fd, buffer, size);
	87	} else {
	88	return qemu_co_send(fd, buffer, size);
	89	}
	90	}
	91
7a5ca864 FB	92	while (offset < size) {
	93	ssize_t len;
	94
	95	if (do_read) {
00aa0040	96	len = qemu_recv(fd, buffer + offset, size - offset, 0);
7a5ca864	97	} else {
03ff3ca3	98	len = send(fd, buffer + offset, size - offset, 0);
7a5ca864 FB	99	}
7a5ca864 FB	100
03ff3ca3 AL	101	if (len == -1)
	102	errno = socket_error();
	103
7a5ca864	104	/* recoverable error */
75818250	105	if (len == -1 && (errno == EAGAIN \|\| errno == EINTR)) {
7a5ca864 FB	106	continue;
	107	}
	108
	109	/* eof */
	110	if (len == 0) {
	111	break;
	112	}
	113
	114	/* unrecoverable error */
	115	if (len == -1) {
	116	return 0;
	117	}
	118
	119	offset += len;
	120	}
	121
	122	return offset;
	123	}
	124
c12504ce NT	125	static void combine_addr(char buf, size_t len, const char address,
c12504ce NT	126	uint16_t port)
7a5ca864	127	{
c12504ce NT	128	/* If the address-part contains a colon, it's an IPv6 IP so needs [] */
	129	if (strstr(address, ":")) {
	130	snprintf(buf, len, "[%s]:%u", address, port);
	131	} else {
	132	snprintf(buf, len, "%s:%u", address, port);
7a5ca864	133	}
7a5ca864 FB	134	}
7a5ca864 FB	135
c12504ce	136	int tcp_socket_outgoing(const char *address, uint16_t port)
7a5ca864	137	{
c12504ce NT	138	char address_and_port[128];
	139	combine_addr(address_and_port, 128, address, port);
	140	return tcp_socket_outgoing_spec(address_and_port);
7a5ca864 FB	141	}
7a5ca864 FB	142
c12504ce	143	int tcp_socket_outgoing_spec(const char *address_and_port)
cd831bd7	144	{
c12504ce	145	return inet_connect(address_and_port, SOCK_STREAM);
cd831bd7 TS	146	}
cd831bd7 TS	147
c12504ce	148	int tcp_socket_incoming(const char *address, uint16_t port)
cd831bd7	149	{
c12504ce NT	150	char address_and_port[128];
	151	combine_addr(address_and_port, 128, address, port);
	152	return tcp_socket_incoming_spec(address_and_port);
	153	}
cd831bd7	154
c12504ce NT	155	int tcp_socket_incoming_spec(const char *address_and_port)
	156	{
	157	char *ostr = NULL;
	158	int olen = 0;
	159	return inet_listen(address_and_port, ostr, olen, SOCK_STREAM, 0);
03ff3ca3	160	}
c12504ce	161
03ff3ca3 AL	162	int unix_socket_incoming(const char *path)
03ff3ca3 AL	163	{
c12504ce NT	164	char *ostr = NULL;
	165	int olen = 0;
	166
	167	return unix_listen(path, ostr, olen);
cd831bd7 TS	168	}
cd831bd7 TS	169
03ff3ca3 AL	170	int unix_socket_outgoing(const char *path)
03ff3ca3 AL	171	{
c12504ce	172	return unix_connect(path);
03ff3ca3	173	}
cd831bd7	174
7a5ca864 FB	175	/* Basic flow
	176
	177	Server Client
	178
	179	Negotiate
	180	Request
	181	Response
	182	Request
	183	Response
	184	...
	185	...
	186	Request (type == 2)
	187	*/
	188
b90fb4b8	189	int nbd_negotiate(int csock, off_t size, uint32_t flags)
7a5ca864	190	{
b2e3d87f NT	191	char buf[8 + 8 + 8 + 128];
	192
	193	/* Negotiate
	194	[ 0 .. 7] passwd ("NBDMAGIC")
	195	[ 8 .. 15] magic (0x00420281861253)
	196	[16 .. 23] size
b90fb4b8 PB	197	[24 .. 27] flags
b90fb4b8 PB	198	[28 .. 151] reserved (0)
b2e3d87f NT	199	*/
	200
	201	TRACE("Beginning negotiation.");
	202	memcpy(buf, "NBDMAGIC", 8);
	203	cpu_to_be64w((uint64_t*)(buf + 8), 0x00420281861253LL);
	204	cpu_to_be64w((uint64_t*)(buf + 16), size);
2c7989a9	205	cpu_to_be32w((uint32_t*)(buf + 24),
7a706633 PB	206	flags \| NBD_FLAG_HAS_FLAGS \| NBD_FLAG_SEND_TRIM \|
7a706633 PB	207	NBD_FLAG_SEND_FLUSH \| NBD_FLAG_SEND_FUA);
b90fb4b8	208	memset(buf + 28, 0, 124);
b2e3d87f NT	209
	210	if (write_sync(csock, buf, sizeof(buf)) != sizeof(buf)) {
	211	LOG("write failed");
	212	errno = EINVAL;
	213	return -1;
	214	}
	215
07f35073	216	TRACE("Negotiation succeeded.");
b2e3d87f NT	217
b2e3d87f NT	218	return 0;
7a5ca864 FB	219	}
7a5ca864 FB	220
1d45f8b5 LV	221	int nbd_receive_negotiate(int csock, const char name, uint32_t flags,
1d45f8b5 LV	222	off_t size, size_t blocksize)
7a5ca864	223	{
b2e3d87f NT	224	char buf[256];
	225	uint64_t magic, s;
	226	uint16_t tmp;
	227
07f35073	228	TRACE("Receiving negotiation.");
b2e3d87f NT	229
	230	if (read_sync(csock, buf, 8) != 8) {
	231	LOG("read failed");
	232	errno = EINVAL;
	233	return -1;
	234	}
	235
	236	buf[8] = '\0';
	237	if (strlen(buf) == 0) {
	238	LOG("server connection closed");
	239	errno = EINVAL;
	240	return -1;
	241	}
	242
	243	TRACE("Magic is %c%c%c%c%c%c%c%c",
	244	qemu_isprint(buf[0]) ? buf[0] : '.',
	245	qemu_isprint(buf[1]) ? buf[1] : '.',
	246	qemu_isprint(buf[2]) ? buf[2] : '.',
	247	qemu_isprint(buf[3]) ? buf[3] : '.',
	248	qemu_isprint(buf[4]) ? buf[4] : '.',
	249	qemu_isprint(buf[5]) ? buf[5] : '.',
	250	qemu_isprint(buf[6]) ? buf[6] : '.',
	251	qemu_isprint(buf[7]) ? buf[7] : '.');
	252
	253	if (memcmp(buf, "NBDMAGIC", 8) != 0) {
	254	LOG("Invalid magic received");
	255	errno = EINVAL;
	256	return -1;
	257	}
	258
	259	if (read_sync(csock, &magic, sizeof(magic)) != sizeof(magic)) {
	260	LOG("read failed");
	261	errno = EINVAL;
	262	return -1;
	263	}
	264	magic = be64_to_cpu(magic);
	265	TRACE("Magic is 0x%" PRIx64, magic);
	266
	267	if (name) {
	268	uint32_t reserved = 0;
	269	uint32_t opt;
	270	uint32_t namesize;
	271
	272	TRACE("Checking magic (opts_magic)");
	273	if (magic != 0x49484156454F5054LL) {
	274	LOG("Bad magic received");
	275	errno = EINVAL;
	276	return -1;
	277	}
	278	if (read_sync(csock, &tmp, sizeof(tmp)) != sizeof(tmp)) {
	279	LOG("flags read failed");
	280	errno = EINVAL;
	281	return -1;
	282	}
	283	*flags = be16_to_cpu(tmp) << 16;
	284	/* reserved for future use */
	285	if (write_sync(csock, &reserved, sizeof(reserved)) !=
	286	sizeof(reserved)) {
	287	LOG("write failed (reserved)");
	288	errno = EINVAL;
	289	return -1;
	290	}
	291	/* write the export name */
	292	magic = cpu_to_be64(magic);
293	if (write_sync(csock, &magic, sizeof(magic)) != sizeof(magic)) {
294	LOG("write failed (magic)");
295	errno = EINVAL;
296	return -1;
297	}
298	opt = cpu_to_be32(NBD_OPT_EXPORT_NAME);
299	if (write_sync(csock, &opt, sizeof(opt)) != sizeof(opt)) {
300	LOG("write failed (opt)");
301	errno = EINVAL;
302	return -1;
303	}
304	namesize = cpu_to_be32(strlen(name));
305	if (write_sync(csock, &namesize, sizeof(namesize)) !=
306	sizeof(namesize)) {
307	LOG("write failed (namesize)");
308	errno = EINVAL;
309	return -1;
310	}
311	if (write_sync(csock, (char*)name, strlen(name)) != strlen(name)) {
312	LOG("write failed (name)");
313	errno = EINVAL;
314	return -1;
315	}
316	} else {
317	TRACE("Checking magic (cli_magic)");
318
319	if (magic != 0x00420281861253LL) {
320	LOG("Bad magic received");
321	errno = EINVAL;
322	return -1;
323	}
324	}
325
326	if (read_sync(csock, &s, sizeof(s)) != sizeof(s)) {
327	LOG("read failed");
328	errno = EINVAL;
329	return -1;
330	}
331	*size = be64_to_cpu(s);
332	*blocksize = 1024;
333	TRACE("Size is %" PRIu64, *size);
334
335	if (!name) {
336	if (read_sync(csock, flags, sizeof(flags)) != sizeof(flags)) {
337	LOG("read failed (flags)");
338	errno = EINVAL;
339	return -1;
340	}
341	*flags = be32_to_cpup(flags);
342	} else {
343	if (read_sync(csock, &tmp, sizeof(tmp)) != sizeof(tmp)) {
344	LOG("read failed (tmp)");
345	errno = EINVAL;
346	return -1;
347	}
348	*flags \|= be32_to_cpu(tmp);
349	}
350	if (read_sync(csock, &buf, 124) != 124) {
351	LOG("read failed (buf)");
352	errno = EINVAL;
353	return -1;
354	}
cd831bd7 TS	355	return 0;
cd831bd7 TS	356	}
7a5ca864	357
b90fb4b8 PB	358	#ifdef __linux__
b90fb4b8 PB	359	int nbd_init(int fd, int csock, uint32_t flags, off_t size, size_t blocksize)
cd831bd7	360	{
3e05c785 CL	361	TRACE("Setting NBD socket");
	362
	363	if (ioctl(fd, NBD_SET_SOCK, csock) == -1) {
	364	int serrno = errno;
	365	LOG("Failed to set NBD socket");
	366	errno = serrno;
	367	return -1;
	368	}
	369
b2e3d87f	370	TRACE("Setting block size to %lu", (unsigned long)blocksize);
7a5ca864	371
b2e3d87f NT	372	if (ioctl(fd, NBD_SET_BLKSIZE, blocksize) == -1) {
	373	int serrno = errno;
	374	LOG("Failed setting NBD block size");
	375	errno = serrno;
	376	return -1;
	377	}
7a5ca864	378
0bfcd599	379	TRACE("Setting size to %zd block(s)", (size_t)(size / blocksize));
7a5ca864	380
b2e3d87f NT	381	if (ioctl(fd, NBD_SET_SIZE_BLOCKS, size / blocksize) == -1) {
	382	int serrno = errno;
	383	LOG("Failed setting size (in blocks)");
	384	errno = serrno;
	385	return -1;
	386	}
7a5ca864	387
b90fb4b8 PB	388	if (flags & NBD_FLAG_READ_ONLY) {
	389	int read_only = 1;
	390	TRACE("Setting readonly attribute");
	391
	392	if (ioctl(fd, BLKROSET, (unsigned long) &read_only) < 0) {
	393	int serrno = errno;
	394	LOG("Failed setting read-only attribute");
	395	errno = serrno;
	396	return -1;
	397	}
	398	}
	399
973b3d0a PB	400	if (ioctl(fd, NBD_SET_FLAGS, flags) < 0
	401	&& errno != ENOTTY) {
	402	int serrno = errno;
	403	LOG("Failed setting flags");
	404	errno = serrno;
	405	return -1;
	406	}
	407
b2e3d87f	408	TRACE("Negotiation ended");
7a5ca864	409
b2e3d87f	410	return 0;
7a5ca864 FB	411	}
	412
	413	int nbd_disconnect(int fd)
	414	{
b2e3d87f NT	415	ioctl(fd, NBD_CLEAR_QUE);
	416	ioctl(fd, NBD_DISCONNECT);
	417	ioctl(fd, NBD_CLEAR_SOCK);
	418	return 0;
7a5ca864 FB	419	}
7a5ca864 FB	420
0a4eb864	421	int nbd_client(int fd)
7a5ca864	422	{
b2e3d87f NT	423	int ret;
b2e3d87f NT	424	int serrno;
7a5ca864	425
b2e3d87f	426	TRACE("Doing NBD loop");
7a5ca864	427
b2e3d87f	428	ret = ioctl(fd, NBD_DO_IT);
74624688 PB	429	if (ret == -1 && errno == EPIPE) {
	430	/* NBD_DO_IT normally returns EPIPE when someone has disconnected
	431	* the socket via NBD_DISCONNECT. We do not want to return 1 in
	432	* that case.
	433	*/
	434	ret = 0;
	435	}
b2e3d87f	436	serrno = errno;
7a5ca864	437
b2e3d87f	438	TRACE("NBD loop returned %d: %s", ret, strerror(serrno));
7a5ca864	439
b2e3d87f NT	440	TRACE("Clearing NBD queue");
b2e3d87f NT	441	ioctl(fd, NBD_CLEAR_QUE);
7a5ca864	442
b2e3d87f NT	443	TRACE("Clearing NBD socket");
b2e3d87f NT	444	ioctl(fd, NBD_CLEAR_SOCK);
7a5ca864	445
b2e3d87f NT	446	errno = serrno;
b2e3d87f NT	447	return ret;
7a5ca864	448	}
03ff3ca3	449	#else
8e72506e	450	int nbd_init(int fd, int csock, uint32_t flags, off_t size, size_t blocksize)
03ff3ca3 AL	451	{
	452	errno = ENOTSUP;
	453	return -1;
	454	}
	455
	456	int nbd_disconnect(int fd)
	457	{
	458	errno = ENOTSUP;
	459	return -1;
	460	}
	461
0a4eb864	462	int nbd_client(int fd)
03ff3ca3 AL	463	{
	464	errno = ENOTSUP;
	465	return -1;
	466	}
	467	#endif
7a5ca864	468
75818250	469	int nbd_send_request(int csock, struct nbd_request *request)
7a5ca864	470	{
b2e3d87f NT	471	uint8_t buf[4 + 4 + 8 + 8 + 4];
	472
	473	cpu_to_be32w((uint32_t*)buf, NBD_REQUEST_MAGIC);
	474	cpu_to_be32w((uint32_t*)(buf + 4), request->type);
	475	cpu_to_be64w((uint64_t*)(buf + 8), request->handle);
	476	cpu_to_be64w((uint64_t*)(buf + 16), request->from);
	477	cpu_to_be32w((uint32_t*)(buf + 24), request->len);
75818250	478
b2e3d87f NT	479	TRACE("Sending request to client: "
	480	"{ .from = %" PRIu64", .len = %u, .handle = %" PRIu64", .type=%i}",
	481	request->from, request->len, request->handle, request->type);
	482
	483	if (write_sync(csock, buf, sizeof(buf)) != sizeof(buf)) {
	484	LOG("writing to socket failed");
	485	errno = EINVAL;
	486	return -1;
	487	}
	488	return 0;
	489	}
75818250 TS	490
	491	static int nbd_receive_request(int csock, struct nbd_request *request)
	492	{
b2e3d87f NT	493	uint8_t buf[4 + 4 + 8 + 8 + 4];
	494	uint32_t magic;
	495
	496	if (read_sync(csock, buf, sizeof(buf)) != sizeof(buf)) {
	497	LOG("read failed");
	498	errno = EINVAL;
	499	return -1;
	500	}
	501
	502	/* Request
	503	[ 0 .. 3] magic (NBD_REQUEST_MAGIC)
	504	[ 4 .. 7] type (0 == READ, 1 == WRITE)
	505	[ 8 .. 15] handle
	506	[16 .. 23] from
	507	[24 .. 27] len
	508	*/
	509
	510	magic = be32_to_cpup((uint32_t*)buf);
	511	request->type = be32_to_cpup((uint32_t*)(buf + 4));
	512	request->handle = be64_to_cpup((uint64_t*)(buf + 8));
	513	request->from = be64_to_cpup((uint64_t*)(buf + 16));
	514	request->len = be32_to_cpup((uint32_t*)(buf + 24));
	515
	516	TRACE("Got request: "
	517	"{ magic = 0x%x, .type = %d, from = %" PRIu64" , len = %u }",
	518	magic, request->type, request->from, request->len);
	519
	520	if (magic != NBD_REQUEST_MAGIC) {
	521	LOG("invalid magic (got 0x%x)", magic);
	522	errno = EINVAL;
	523	return -1;
	524	}
	525	return 0;
75818250 TS	526	}
	527
	528	int nbd_receive_reply(int csock, struct nbd_reply *reply)
	529	{
b2e3d87f NT	530	uint8_t buf[NBD_REPLY_SIZE];
	531	uint32_t magic;
	532
	533	memset(buf, 0xAA, sizeof(buf));
	534
	535	if (read_sync(csock, buf, sizeof(buf)) != sizeof(buf)) {
	536	LOG("read failed");
	537	errno = EINVAL;
	538	return -1;
	539	}
	540
	541	/* Reply
	542	[ 0 .. 3] magic (NBD_REPLY_MAGIC)
	543	[ 4 .. 7] error (0 == no error)
	544	[ 7 .. 15] handle
	545	*/
	546
	547	magic = be32_to_cpup((uint32_t*)buf);
	548	reply->error = be32_to_cpup((uint32_t*)(buf + 4));
	549	reply->handle = be64_to_cpup((uint64_t*)(buf + 8));
	550
	551	TRACE("Got reply: "
	552	"{ magic = 0x%x, .error = %d, handle = %" PRIu64" }",
	553	magic, reply->error, reply->handle);
	554
	555	if (magic != NBD_REPLY_MAGIC) {
	556	LOG("invalid magic (got 0x%x)", magic);
	557	errno = EINVAL;
	558	return -1;
	559	}
	560	return 0;
75818250 TS	561	}
	562
	563	static int nbd_send_reply(int csock, struct nbd_reply *reply)
	564	{
b2e3d87f NT	565	uint8_t buf[4 + 4 + 8];
	566
	567	/* Reply
	568	[ 0 .. 3] magic (NBD_REPLY_MAGIC)
	569	[ 4 .. 7] error (0 == no error)
	570	[ 7 .. 15] handle
	571	*/
	572	cpu_to_be32w((uint32_t*)buf, NBD_REPLY_MAGIC);
	573	cpu_to_be32w((uint32_t*)(buf + 4), reply->error);
	574	cpu_to_be64w((uint64_t*)(buf + 8), reply->handle);
	575
	576	TRACE("Sending response to client");
	577
	578	if (write_sync(csock, buf, sizeof(buf)) != sizeof(buf)) {
	579	LOG("writing to socket failed");
	580	errno = EINVAL;
	581	return -1;
	582	}
	583	return 0;
75818250	584	}
7a5ca864	585
94607e7a PB	586	int nbd_trip(BlockDriverState *bs, int csock, off_t size,
94607e7a PB	587	uint64_t dev_offset, uint32_t nbdflags,
3777b09f	588	uint8_t *data)
75818250	589	{
b2e3d87f NT	590	struct nbd_request request;
b2e3d87f NT	591	struct nbd_reply reply;
adcf6302	592	int ret;
b2e3d87f NT	593
	594	TRACE("Reading request.");
	595
	596	if (nbd_receive_request(csock, &request) == -1)
	597	return -1;
	598
3777b09f	599	if (request.len + NBD_REPLY_SIZE > NBD_BUFFER_SIZE) {
b2e3d87f	600	LOG("len (%u) is larger than max len (%u)",
3777b09f	601	request.len + NBD_REPLY_SIZE, NBD_BUFFER_SIZE);
b2e3d87f NT	602	errno = EINVAL;
	603	return -1;
	604	}
	605
	606	if ((request.from + request.len) < request.from) {
	607	LOG("integer overflow detected! "
	608	"you're probably being attacked");
	609	errno = EINVAL;
	610	return -1;
	611	}
	612
	613	if ((request.from + request.len) > size) {
	614	LOG("From: %" PRIu64 ", Len: %u, Size: %" PRIu64
	615	", Offset: %" PRIu64 "\n",
b9e82a59	616	request.from, request.len, (uint64_t)size, dev_offset);
b2e3d87f NT	617	LOG("requested operation past EOF--bad client?");
	618	errno = EINVAL;
	619	return -1;
	620	}
	621
	622	TRACE("Decoding type");
	623
	624	reply.handle = request.handle;
	625	reply.error = 0;
	626
2c7989a9	627	switch (request.type & NBD_CMD_MASK_COMMAND) {
b2e3d87f NT	628	case NBD_CMD_READ:
	629	TRACE("Request type is READ");
	630
adcf6302 PB	631	ret = bdrv_read(bs, (request.from + dev_offset) / 512,
	632	data + NBD_REPLY_SIZE,
	633	request.len / 512);
	634	if (ret < 0) {
b2e3d87f	635	LOG("reading from file failed");
adcf6302 PB	636	reply.error = -ret;
adcf6302 PB	637	request.len = 0;
b2e3d87f	638	}
b2e3d87f NT	639
	640	TRACE("Read %u byte(s)", request.len);
	641
	642	/* Reply
	643	[ 0 .. 3] magic (NBD_REPLY_MAGIC)
	644	[ 4 .. 7] error (0 == no error)
	645	[ 7 .. 15] handle
	646	*/
	647
	648	cpu_to_be32w((uint32_t*)data, NBD_REPLY_MAGIC);
	649	cpu_to_be32w((uint32_t*)(data + 4), reply.error);
	650	cpu_to_be64w((uint64_t*)(data + 8), reply.handle);
	651
	652	TRACE("Sending data to client");
	653
	654	if (write_sync(csock, data,
	655	request.len + NBD_REPLY_SIZE) !=
	656	request.len + NBD_REPLY_SIZE) {
	657	LOG("writing to socket failed");
	658	errno = EINVAL;
	659	return -1;
	660	}
	661	break;
	662	case NBD_CMD_WRITE:
	663	TRACE("Request type is WRITE");
	664
	665	TRACE("Reading %u byte(s)", request.len);
	666
	667	if (read_sync(csock, data, request.len) != request.len) {
	668	LOG("reading from socket failed");
	669	errno = EINVAL;
	670	return -1;
	671	}
	672
b90fb4b8	673	if (nbdflags & NBD_FLAG_READ_ONLY) {
b2e3d87f NT	674	TRACE("Server is read-only, return error");
	675	reply.error = 1;
	676	} else {
	677	TRACE("Writing to device");
	678
adcf6302 PB	679	ret = bdrv_write(bs, (request.from + dev_offset) / 512,
	680	data, request.len / 512);
	681	if (ret < 0) {
b2e3d87f	682	LOG("writing to file failed");
adcf6302 PB	683	reply.error = -ret;
adcf6302 PB	684	request.len = 0;
b2e3d87f NT	685	}
b2e3d87f NT	686
2c7989a9 PB	687	if (request.type & NBD_CMD_FLAG_FUA) {
	688	ret = bdrv_flush(bs);
	689	if (ret < 0) {
	690	LOG("flush failed");
	691	reply.error = -ret;
	692	}
	693	}
b2e3d87f NT	694	}
	695
	696	if (nbd_send_reply(csock, &reply) == -1)
	697	return -1;
	698	break;
	699	case NBD_CMD_DISC:
	700	TRACE("Request type is DISCONNECT");
	701	errno = 0;
	702	return 1;
1486d04a PB	703	case NBD_CMD_FLUSH:
	704	TRACE("Request type is FLUSH");
	705
	706	ret = bdrv_flush(bs);
	707	if (ret < 0) {
	708	LOG("flush failed");
	709	reply.error = -ret;
	710	}
	711
7a706633 PB	712	if (nbd_send_reply(csock, &reply) == -1)
	713	return -1;
	714	break;
	715	case NBD_CMD_TRIM:
	716	TRACE("Request type is TRIM");
	717	ret = bdrv_discard(bs, (request.from + dev_offset) / 512,
	718	request.len / 512);
	719	if (ret < 0) {
	720	LOG("discard failed");
	721	reply.error = -ret;
	722	}
1486d04a PB	723	if (nbd_send_reply(csock, &reply) == -1)
	724	return -1;
	725	break;
b2e3d87f NT	726	default:
	727	LOG("invalid request type (%u) received", request.type);
	728	errno = EINVAL;
	729	return -1;
	730	}
	731
	732	TRACE("Request/Reply complete");
	733
	734	return 0;
7a5ca864	735	}