[qemu.git] / nbd / client.c

/*
 *  Copyright (C) 2005  Anthony Liguori <[email protected]>
 *
 *  Network Block Device Client Side
 *
 *  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 "qemu/osdep.h"
#include "qapi/error.h"
#include "nbd-internal.h"

static int nbd_errno_to_system_errno(int err)
{
    switch (err) {
    case NBD_SUCCESS:
        return 0;
    case NBD_EPERM:
        return EPERM;
    case NBD_EIO:
        return EIO;
    case NBD_ENOMEM:
        return ENOMEM;
    case NBD_ENOSPC:
        return ENOSPC;
    case NBD_EINVAL:
    default:
        return EINVAL;
    }
}

/* Definitions for opaque data types */

static QTAILQ_HEAD(, NBDExport) exports = QTAILQ_HEAD_INITIALIZER(exports);

/* That's all folks */

/* Basic flow for negotiation

   Server         Client
   Negotiate

   or

   Server         Client
   Negotiate #1
                  Option
   Negotiate #2

   ----

   followed by

   Server         Client
                  Request
   Response
                  Request
   Response
                  ...
   ...
                  Request (type == 2)

*/


static int nbd_handle_reply_err(uint32_t opt, uint32_t type, Error **errp)
{
    if (!(type & (1 << 31))) {
        return 0;
    }

    switch (type) {
    case NBD_REP_ERR_UNSUP:
        error_setg(errp, "Unsupported option type %x", opt);
        break;

    case NBD_REP_ERR_POLICY:
        error_setg(errp, "Denied by server for option %x", opt);
        break;

    case NBD_REP_ERR_INVALID:
        error_setg(errp, "Invalid data length for option %x", opt);
        break;

    case NBD_REP_ERR_TLS_REQD:
        error_setg(errp, "TLS negotiation required before option %x", opt);
        break;

    default:
        error_setg(errp, "Unknown error code when asking for option %x", opt);
        break;
    }

    return -1;
}

static int nbd_receive_list(QIOChannel *ioc, char **name, Error **errp)
{
    uint64_t magic;
    uint32_t opt;
    uint32_t type;
    uint32_t len;
    uint32_t namelen;

    *name = NULL;
    if (read_sync(ioc, &magic, sizeof(magic)) != sizeof(magic)) {
        error_setg(errp, "failed to read list option magic");
        return -1;
    }
    magic = be64_to_cpu(magic);
    if (magic != NBD_REP_MAGIC) {
        error_setg(errp, "Unexpected option list magic");
        return -1;
    }
    if (read_sync(ioc, &opt, sizeof(opt)) != sizeof(opt)) {
        error_setg(errp, "failed to read list option");
        return -1;
    }
    opt = be32_to_cpu(opt);
    if (opt != NBD_OPT_LIST) {
        error_setg(errp, "Unexpected option type %x expected %x",
                   opt, NBD_OPT_LIST);
        return -1;
    }

    if (read_sync(ioc, &type, sizeof(type)) != sizeof(type)) {
        error_setg(errp, "failed to read list option type");
        return -1;
    }
    type = be32_to_cpu(type);
    if (type == NBD_REP_ERR_UNSUP) {
        return 0;
    }
    if (nbd_handle_reply_err(opt, type, errp) < 0) {
        return -1;
    }

    if (read_sync(ioc, &len, sizeof(len)) != sizeof(len)) {
        error_setg(errp, "failed to read option length");
        return -1;
    }
    len = be32_to_cpu(len);

    if (type == NBD_REP_ACK) {
        if (len != 0) {
            error_setg(errp, "length too long for option end");
            return -1;
        }
    } else if (type == NBD_REP_SERVER) {
        if (read_sync(ioc, &namelen, sizeof(namelen)) != sizeof(namelen)) {
            error_setg(errp, "failed to read option name length");
            return -1;
        }
        namelen = be32_to_cpu(namelen);
        if (len != (namelen + sizeof(namelen))) {
            error_setg(errp, "incorrect option mame length");
            return -1;
        }
        if (namelen > 255) {
            error_setg(errp, "export name length too long %d", namelen);
            return -1;
        }

        *name = g_new0(char, namelen + 1);
        if (read_sync(ioc, *name, namelen) != namelen) {
            error_setg(errp, "failed to read export name");
            g_free(*name);
            *name = NULL;
            return -1;
        }
        (*name)[namelen] = '\0';
    } else {
        error_setg(errp, "Unexpected reply type %x expected %x",
                   type, NBD_REP_SERVER);
        return -1;
    }
    return 1;
}


static int nbd_receive_query_exports(QIOChannel *ioc,
                                     const char *wantname,
                                     Error **errp)
{
    uint64_t magic = cpu_to_be64(NBD_OPTS_MAGIC);
    uint32_t opt = cpu_to_be32(NBD_OPT_LIST);
    uint32_t length = 0;
    bool foundExport = false;

    TRACE("Querying export list");
    if (write_sync(ioc, &magic, sizeof(magic)) != sizeof(magic)) {
        error_setg(errp, "Failed to send list option magic");
        return -1;
    }

    if (write_sync(ioc, &opt, sizeof(opt)) != sizeof(opt)) {
        error_setg(errp, "Failed to send list option number");
        return -1;
    }

    if (write_sync(ioc, &length, sizeof(length)) != sizeof(length)) {
        error_setg(errp, "Failed to send list option length");
        return -1;
    }

    TRACE("Reading available export names");
    while (1) {
        char *name = NULL;
        int ret = nbd_receive_list(ioc, &name, errp);

        if (ret < 0) {
            g_free(name);
            name = NULL;
            return -1;
        }
        if (ret == 0) {
            /* Server doesn't support export listing, so
             * we will just assume an export with our
             * wanted name exists */
            foundExport = true;
            break;
        }
        if (name == NULL) {
            TRACE("End of export name list");
            break;
        }
        if (g_str_equal(name, wantname)) {
            foundExport = true;
            TRACE("Found desired export name '%s'", name);
        } else {
            TRACE("Ignored export name '%s'", name);
        }
        g_free(name);
    }

    if (!foundExport) {
        error_setg(errp, "No export with name '%s' available", wantname);
        return -1;
    }

    return 0;
}

static QIOChannel *nbd_receive_starttls(QIOChannel *ioc,
                                        QCryptoTLSCreds *tlscreds,
                                        const char *hostname, Error **errp)
{
    uint64_t magic = cpu_to_be64(NBD_OPTS_MAGIC);
    uint32_t opt = cpu_to_be32(NBD_OPT_STARTTLS);
    uint32_t length = 0;
    uint32_t type;
    QIOChannelTLS *tioc;
    struct NBDTLSHandshakeData data = { 0 };

    TRACE("Requesting TLS from server");
    if (write_sync(ioc, &magic, sizeof(magic)) != sizeof(magic)) {
        error_setg(errp, "Failed to send option magic");
        return NULL;
    }

    if (write_sync(ioc, &opt, sizeof(opt)) != sizeof(opt)) {
        error_setg(errp, "Failed to send option number");
        return NULL;
    }

    if (write_sync(ioc, &length, sizeof(length)) != sizeof(length)) {
        error_setg(errp, "Failed to send option length");
        return NULL;
    }

    TRACE("Getting TLS reply from server1");
    if (read_sync(ioc, &magic, sizeof(magic)) != sizeof(magic)) {
        error_setg(errp, "failed to read option magic");
        return NULL;
    }
    magic = be64_to_cpu(magic);
    if (magic != NBD_REP_MAGIC) {
        error_setg(errp, "Unexpected option magic");
        return NULL;
    }
    TRACE("Getting TLS reply from server2");
    if (read_sync(ioc, &opt, sizeof(opt)) != sizeof(opt)) {
        error_setg(errp, "failed to read option");
        return NULL;
    }
    opt = be32_to_cpu(opt);
    if (opt != NBD_OPT_STARTTLS) {
        error_setg(errp, "Unexpected option type %x expected %x",
                   opt, NBD_OPT_STARTTLS);
        return NULL;
    }

    TRACE("Getting TLS reply from server");
    if (read_sync(ioc, &type, sizeof(type)) != sizeof(type)) {
        error_setg(errp, "failed to read option type");
        return NULL;
    }
    type = be32_to_cpu(type);
    if (type != NBD_REP_ACK) {
        error_setg(errp, "Server rejected request to start TLS %x",
                   type);
        return NULL;
    }

    TRACE("Getting TLS reply from server");
    if (read_sync(ioc, &length, sizeof(length)) != sizeof(length)) {
        error_setg(errp, "failed to read option length");
        return NULL;
    }
    length = be32_to_cpu(length);
    if (length != 0) {
        error_setg(errp, "Start TLS reponse was not zero %x",
                   length);
        return NULL;
    }

    TRACE("TLS request approved, setting up TLS");
    tioc = qio_channel_tls_new_client(ioc, tlscreds, hostname, errp);
    if (!tioc) {
        return NULL;
    }
    data.loop = g_main_loop_new(g_main_context_default(), FALSE);
    TRACE("Starting TLS hanshake");
    qio_channel_tls_handshake(tioc,
                              nbd_tls_handshake,
                              &data,
                              NULL);

    if (!data.complete) {
        g_main_loop_run(data.loop);
    }
    g_main_loop_unref(data.loop);
    if (data.error) {
        error_propagate(errp, data.error);
        object_unref(OBJECT(tioc));
        return NULL;
    }

    return QIO_CHANNEL(tioc);
}


int nbd_receive_negotiate(QIOChannel *ioc, const char *name, uint32_t *flags,
                          QCryptoTLSCreds *tlscreds, const char *hostname,
                          QIOChannel **outioc,
                          off_t *size, Error **errp)
{
    char buf[256];
    uint64_t magic, s;
    int rc;

    TRACE("Receiving negotiation tlscreds=%p hostname=%s.",
          tlscreds, hostname ? hostname : "<null>");

    rc = -EINVAL;

    if (outioc) {
        *outioc = NULL;
    }
    if (tlscreds && !outioc) {
        error_setg(errp, "Output I/O channel required for TLS");
        goto fail;
    }

    if (read_sync(ioc, buf, 8) != 8) {
        error_setg(errp, "Failed to read data");
        goto fail;
    }

    buf[8] = '\0';
    if (strlen(buf) == 0) {
        error_setg(errp, "Server connection closed unexpectedly");
        goto fail;
    }

    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) {
        error_setg(errp, "Invalid magic received");
        goto fail;
    }

    if (read_sync(ioc, &magic, sizeof(magic)) != sizeof(magic)) {
        error_setg(errp, "Failed to read magic");
        goto fail;
    }
    magic = be64_to_cpu(magic);
    TRACE("Magic is 0x%" PRIx64, magic);

    if (magic == NBD_OPTS_MAGIC) {
        uint32_t clientflags = 0;
        uint32_t opt;
        uint32_t namesize;
        uint16_t globalflags;
        uint16_t exportflags;
        bool fixedNewStyle = false;

        if (read_sync(ioc, &globalflags, sizeof(globalflags)) !=
            sizeof(globalflags)) {
            error_setg(errp, "Failed to read server flags");
            goto fail;
        }
        globalflags = be16_to_cpu(globalflags);
        *flags = globalflags << 16;
        TRACE("Global flags are %x", globalflags);
        if (globalflags & NBD_FLAG_FIXED_NEWSTYLE) {
            fixedNewStyle = true;
            TRACE("Server supports fixed new style");
            clientflags |= NBD_FLAG_C_FIXED_NEWSTYLE;
        }
        /* client requested flags */
        clientflags = cpu_to_be32(clientflags);
        if (write_sync(ioc, &clientflags, sizeof(clientflags)) !=
            sizeof(clientflags)) {
            error_setg(errp, "Failed to send clientflags field");
            goto fail;
        }
        if (tlscreds) {
            if (fixedNewStyle) {
                *outioc = nbd_receive_starttls(ioc, tlscreds, hostname, errp);
                if (!*outioc) {
                    goto fail;
                }
                ioc = *outioc;
            } else {
                error_setg(errp, "Server does not support STARTTLS");
                goto fail;
            }
        }
        if (!name) {
            TRACE("Using default NBD export name \"\"");
            name = "";
        }
        if (fixedNewStyle) {
            /* Check our desired export is present in the
             * server export list. Since NBD_OPT_EXPORT_NAME
             * cannot return an error message, running this
             * query gives us good error reporting if the
             * server required TLS
             */
            if (nbd_receive_query_exports(ioc, name, errp) < 0) {
                goto fail;
            }
        }
        /* write the export name */
        magic = cpu_to_be64(magic);
        if (write_sync(ioc, &magic, sizeof(magic)) != sizeof(magic)) {
            error_setg(errp, "Failed to send export name magic");
            goto fail;
        }
        opt = cpu_to_be32(NBD_OPT_EXPORT_NAME);
        if (write_sync(ioc, &opt, sizeof(opt)) != sizeof(opt)) {
            error_setg(errp, "Failed to send export name option number");
            goto fail;
        }
        namesize = cpu_to_be32(strlen(name));
        if (write_sync(ioc, &namesize, sizeof(namesize)) !=
            sizeof(namesize)) {
            error_setg(errp, "Failed to send export name length");
            goto fail;
        }
        if (write_sync(ioc, (char *)name, strlen(name)) != strlen(name)) {
            error_setg(errp, "Failed to send export name");
            goto fail;
        }

        if (read_sync(ioc, &s, sizeof(s)) != sizeof(s)) {
            error_setg(errp, "Failed to read export length");
            goto fail;
        }
        *size = be64_to_cpu(s);
        TRACE("Size is %" PRIu64, *size);

        if (read_sync(ioc, &exportflags, sizeof(exportflags)) !=
            sizeof(exportflags)) {
            error_setg(errp, "Failed to read export flags");
            goto fail;
        }
        exportflags = be16_to_cpu(exportflags);
        *flags |= exportflags;
        TRACE("Export flags are %x", exportflags);
    } else if (magic == NBD_CLIENT_MAGIC) {
        if (name) {
            error_setg(errp, "Server does not support export names");
            goto fail;
        }
        if (tlscreds) {
            error_setg(errp, "Server does not support STARTTLS");
            goto fail;
        }

        if (read_sync(ioc, &s, sizeof(s)) != sizeof(s)) {
            error_setg(errp, "Failed to read export length");
            goto fail;
        }
        *size = be64_to_cpu(s);
        TRACE("Size is %" PRIu64, *size);

        if (read_sync(ioc, flags, sizeof(*flags)) != sizeof(*flags)) {
            error_setg(errp, "Failed to read export flags");
            goto fail;
        }
        *flags = be32_to_cpup(flags);
    } else {
        error_setg(errp, "Bad magic received");
        goto fail;
    }

    if (read_sync(ioc, &buf, 124) != 124) {
        error_setg(errp, "Failed to read reserved block");
        goto fail;
    }
    rc = 0;

fail:
    return rc;
}

#ifdef __linux__
int nbd_init(int fd, QIOChannelSocket *sioc, uint32_t flags, off_t size)
{
    TRACE("Setting NBD socket");

    if (ioctl(fd, NBD_SET_SOCK, sioc->fd) < 0) {
        int serrno = errno;
        LOG("Failed to set NBD socket");
        return -serrno;
    }

    TRACE("Setting block size to %lu", (unsigned long)BDRV_SECTOR_SIZE);

    if (ioctl(fd, NBD_SET_BLKSIZE, (size_t)BDRV_SECTOR_SIZE) < 0) {
        int serrno = errno;
        LOG("Failed setting NBD block size");
        return -serrno;
    }

    TRACE("Setting size to %zd block(s)", (size_t)(size / BDRV_SECTOR_SIZE));

    if (ioctl(fd, NBD_SET_SIZE_BLOCKS, (size_t)(size / BDRV_SECTOR_SIZE)) < 0) {
        int serrno = errno;
        LOG("Failed setting size (in blocks)");
        return -serrno;
    }

    if (ioctl(fd, NBD_SET_FLAGS, flags) < 0) {
        if (errno == ENOTTY) {
            int read_only = (flags & NBD_FLAG_READ_ONLY) != 0;
            TRACE("Setting readonly attribute");

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

    TRACE("Negotiation ended");

    return 0;
}

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

    TRACE("Doing NBD loop");

    ret = ioctl(fd, NBD_DO_IT);
    if (ret < 0 && 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, QIOChannelSocket *ioc, uint32_t flags, off_t size)
{
    return -ENOTSUP;
}

int nbd_client(int fd)
{
    return -ENOTSUP;
}
#endif

ssize_t nbd_send_request(QIOChannel *ioc, struct nbd_request *request)
{
    uint8_t buf[NBD_REQUEST_SIZE];
    ssize_t ret;

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

    ret = write_sync(ioc, buf, sizeof(buf));
    if (ret < 0) {
        return ret;
    }

    if (ret != sizeof(buf)) {
        LOG("writing to socket failed");
        return -EINVAL;
    }
    return 0;
}

ssize_t nbd_receive_reply(QIOChannel *ioc, struct nbd_reply *reply)
{
    uint8_t buf[NBD_REPLY_SIZE];
    uint32_t magic;
    ssize_t ret;

    ret = read_sync(ioc, buf, sizeof(buf));
    if (ret < 0) {
        return ret;
    }

    if (ret != sizeof(buf)) {
        LOG("read failed");
        return -EINVAL;
    }

    /* 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));

    reply->error = nbd_errno_to_system_errno(reply->error);

    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);
        return -EINVAL;
    }
    return 0;
}
Commit	Line	Data
798bfe00 FZ	1	/*
	2	* Copyright (C) 2005 Anthony Liguori <[email protected]>
	3	*
	4	* Network Block Device Client Side
	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, see <http://www.gnu.org/licenses/>.
	17	*/
	18
d38ea87a	19	#include "qemu/osdep.h"
da34e65c	20	#include "qapi/error.h"
798bfe00 FZ	21	#include "nbd-internal.h"
	22
	23	static int nbd_errno_to_system_errno(int err)
	24	{
	25	switch (err) {
	26	case NBD_SUCCESS:
	27	return 0;
	28	case NBD_EPERM:
	29	return EPERM;
	30	case NBD_EIO:
	31	return EIO;
	32	case NBD_ENOMEM:
	33	return ENOMEM;
	34	case NBD_ENOSPC:
	35	return ENOSPC;
	36	case NBD_EINVAL:
	37	default:
	38	return EINVAL;
	39	}
	40	}
	41
	42	/* Definitions for opaque data types */
	43
	44	static QTAILQ_HEAD(, NBDExport) exports = QTAILQ_HEAD_INITIALIZER(exports);
	45
	46	/* That's all folks */
	47
	48	/* Basic flow for negotiation
	49
	50	Server Client
	51	Negotiate
	52
	53	or
	54
	55	Server Client
	56	Negotiate #1
	57	Option
	58	Negotiate #2
	59
	60	----
	61
	62	followed by
	63
	64	Server Client
	65	Request
	66	Response
	67	Request
	68	Response
	69	...
	70	...
	71	Request (type == 2)
	72
	73	*/
	74
9344e5f5 DB	75
	76	static int nbd_handle_reply_err(uint32_t opt, uint32_t type, Error **errp)
	77	{
	78	if (!(type & (1 << 31))) {
	79	return 0;
	80	}
	81
	82	switch (type) {
	83	case NBD_REP_ERR_UNSUP:
	84	error_setg(errp, "Unsupported option type %x", opt);
	85	break;
	86
f95910fe DB	87	case NBD_REP_ERR_POLICY:
	88	error_setg(errp, "Denied by server for option %x", opt);
	89	break;
	90
9344e5f5 DB	91	case NBD_REP_ERR_INVALID:
	92	error_setg(errp, "Invalid data length for option %x", opt);
	93	break;
	94
f95910fe DB	95	case NBD_REP_ERR_TLS_REQD:
	96	error_setg(errp, "TLS negotiation required before option %x", opt);
	97	break;
	98
9344e5f5 DB	99	default:
	100	error_setg(errp, "Unknown error code when asking for option %x", opt);
	101	break;
	102	}
	103
	104	return -1;
	105	}
	106
	107	static int nbd_receive_list(QIOChannel ioc, char name, Error *errp)
	108	{
	109	uint64_t magic;
	110	uint32_t opt;
	111	uint32_t type;
	112	uint32_t len;
	113	uint32_t namelen;
	114
	115	*name = NULL;
	116	if (read_sync(ioc, &magic, sizeof(magic)) != sizeof(magic)) {
	117	error_setg(errp, "failed to read list option magic");
	118	return -1;
	119	}
	120	magic = be64_to_cpu(magic);
	121	if (magic != NBD_REP_MAGIC) {
	122	error_setg(errp, "Unexpected option list magic");
	123	return -1;
	124	}
	125	if (read_sync(ioc, &opt, sizeof(opt)) != sizeof(opt)) {
	126	error_setg(errp, "failed to read list option");
	127	return -1;
	128	}
	129	opt = be32_to_cpu(opt);
	130	if (opt != NBD_OPT_LIST) {
	131	error_setg(errp, "Unexpected option type %x expected %x",
	132	opt, NBD_OPT_LIST);
	133	return -1;
	134	}
	135
	136	if (read_sync(ioc, &type, sizeof(type)) != sizeof(type)) {
	137	error_setg(errp, "failed to read list option type");
	138	return -1;
	139	}
	140	type = be32_to_cpu(type);
	141	if (type == NBD_REP_ERR_UNSUP) {
	142	return 0;
	143	}
	144	if (nbd_handle_reply_err(opt, type, errp) < 0) {
	145	return -1;
	146	}
	147
	148	if (read_sync(ioc, &len, sizeof(len)) != sizeof(len)) {
	149	error_setg(errp, "failed to read option length");
	150	return -1;
	151	}
	152	len = be32_to_cpu(len);
	153
	154	if (type == NBD_REP_ACK) {
	155	if (len != 0) {
	156	error_setg(errp, "length too long for option end");
	157	return -1;
	158	}
	159	} else if (type == NBD_REP_SERVER) {
	160	if (read_sync(ioc, &namelen, sizeof(namelen)) != sizeof(namelen)) {
	161	error_setg(errp, "failed to read option name length");
	162	return -1;
163	}
164	namelen = be32_to_cpu(namelen);
165	if (len != (namelen + sizeof(namelen))) {
166	error_setg(errp, "incorrect option mame length");
167	return -1;
168	}
169	if (namelen > 255) {
170	error_setg(errp, "export name length too long %d", namelen);
171	return -1;
172	}
173
174	*name = g_new0(char, namelen + 1);
175	if (read_sync(ioc, *name, namelen) != namelen) {
176	error_setg(errp, "failed to read export name");
177	g_free(*name);
178	*name = NULL;
179	return -1;
180	}
181	(*name)[namelen] = '\0';
182	} else {
183	error_setg(errp, "Unexpected reply type %x expected %x",
184	type, NBD_REP_SERVER);
185	return -1;
186	}
187	return 1;
188	}
189
190
191	static int nbd_receive_query_exports(QIOChannel *ioc,
192	const char *wantname,
193	Error **errp)
194	{
195	uint64_t magic = cpu_to_be64(NBD_OPTS_MAGIC);
196	uint32_t opt = cpu_to_be32(NBD_OPT_LIST);
197	uint32_t length = 0;
198	bool foundExport = false;
199
200	TRACE("Querying export list");
201	if (write_sync(ioc, &magic, sizeof(magic)) != sizeof(magic)) {
202	error_setg(errp, "Failed to send list option magic");
203	return -1;
204	}
205
206	if (write_sync(ioc, &opt, sizeof(opt)) != sizeof(opt)) {
207	error_setg(errp, "Failed to send list option number");
208	return -1;
209	}
210
211	if (write_sync(ioc, &length, sizeof(length)) != sizeof(length)) {
212	error_setg(errp, "Failed to send list option length");
213	return -1;
214	}
215
216	TRACE("Reading available export names");
217	while (1) {
218	char *name = NULL;
219	int ret = nbd_receive_list(ioc, &name, errp);
220
221	if (ret < 0) {
222	g_free(name);
223	name = NULL;
224	return -1;
225	}
226	if (ret == 0) {
227	/* Server doesn't support export listing, so
228	* we will just assume an export with our
229	* wanted name exists */
230	foundExport = true;
231	break;
232	}
233	if (name == NULL) {
234	TRACE("End of export name list");
235	break;
236	}
237	if (g_str_equal(name, wantname)) {
238	foundExport = true;
239	TRACE("Found desired export name '%s'", name);
240	} else {
241	TRACE("Ignored export name '%s'", name);
242	}
243	g_free(name);
244	}
245
246	if (!foundExport) {
247	error_setg(errp, "No export with name '%s' available", wantname);
248	return -1;
249	}
250
251	return 0;
252	}
253
f95910fe DB	254	static QIOChannel nbd_receive_starttls(QIOChannel ioc,
	255	QCryptoTLSCreds *tlscreds,
	256	const char hostname, Error *errp)
	257	{
	258	uint64_t magic = cpu_to_be64(NBD_OPTS_MAGIC);
	259	uint32_t opt = cpu_to_be32(NBD_OPT_STARTTLS);
	260	uint32_t length = 0;
	261	uint32_t type;
	262	QIOChannelTLS *tioc;
	263	struct NBDTLSHandshakeData data = { 0 };
	264
	265	TRACE("Requesting TLS from server");
	266	if (write_sync(ioc, &magic, sizeof(magic)) != sizeof(magic)) {
	267	error_setg(errp, "Failed to send option magic");
	268	return NULL;
	269	}
	270
	271	if (write_sync(ioc, &opt, sizeof(opt)) != sizeof(opt)) {
	272	error_setg(errp, "Failed to send option number");
	273	return NULL;
	274	}
	275
	276	if (write_sync(ioc, &length, sizeof(length)) != sizeof(length)) {
	277	error_setg(errp, "Failed to send option length");
	278	return NULL;
	279	}
	280
	281	TRACE("Getting TLS reply from server1");
	282	if (read_sync(ioc, &magic, sizeof(magic)) != sizeof(magic)) {
	283	error_setg(errp, "failed to read option magic");
	284	return NULL;
	285	}
	286	magic = be64_to_cpu(magic);
	287	if (magic != NBD_REP_MAGIC) {
	288	error_setg(errp, "Unexpected option magic");
	289	return NULL;
	290	}
	291	TRACE("Getting TLS reply from server2");
	292	if (read_sync(ioc, &opt, sizeof(opt)) != sizeof(opt)) {
	293	error_setg(errp, "failed to read option");
	294	return NULL;
	295	}
	296	opt = be32_to_cpu(opt);
	297	if (opt != NBD_OPT_STARTTLS) {
	298	error_setg(errp, "Unexpected option type %x expected %x",
	299	opt, NBD_OPT_STARTTLS);
	300	return NULL;
	301	}
	302
	303	TRACE("Getting TLS reply from server");
	304	if (read_sync(ioc, &type, sizeof(type)) != sizeof(type)) {
	305	error_setg(errp, "failed to read option type");
	306	return NULL;
	307	}
	308	type = be32_to_cpu(type);
	309	if (type != NBD_REP_ACK) {
	310	error_setg(errp, "Server rejected request to start TLS %x",
	311	type);
	312	return NULL;
	313	}
	314
	315	TRACE("Getting TLS reply from server");
	316	if (read_sync(ioc, &length, sizeof(length)) != sizeof(length)) {
	317	error_setg(errp, "failed to read option length");
318	return NULL;
319	}
320	length = be32_to_cpu(length);
321	if (length != 0) {
322	error_setg(errp, "Start TLS reponse was not zero %x",
323	length);
324	return NULL;
325	}
326
327	TRACE("TLS request approved, setting up TLS");
328	tioc = qio_channel_tls_new_client(ioc, tlscreds, hostname, errp);
329	if (!tioc) {
330	return NULL;
331	}
332	data.loop = g_main_loop_new(g_main_context_default(), FALSE);
333	TRACE("Starting TLS hanshake");
334	qio_channel_tls_handshake(tioc,
335	nbd_tls_handshake,
336	&data,
337	NULL);
338
339	if (!data.complete) {
340	g_main_loop_run(data.loop);
341	}
342	g_main_loop_unref(data.loop);
343	if (data.error) {
344	error_propagate(errp, data.error);
345	object_unref(OBJECT(tioc));
346	return NULL;
347	}
348
349	return QIO_CHANNEL(tioc);
350	}
351
352
1c778ef7	353	int nbd_receive_negotiate(QIOChannel ioc, const char name, uint32_t *flags,
f95910fe DB	354	QCryptoTLSCreds tlscreds, const char hostname,
f95910fe DB	355	QIOChannel **outioc,
798bfe00 FZ	356	off_t size, Error *errp)
	357	{
	358	char buf[256];
	359	uint64_t magic, s;
798bfe00 FZ	360	int rc;
798bfe00 FZ	361
f95910fe DB	362	TRACE("Receiving negotiation tlscreds=%p hostname=%s.",
f95910fe DB	363	tlscreds, hostname ? hostname : "<null>");
798bfe00 FZ	364
	365	rc = -EINVAL;
	366
f95910fe DB	367	if (outioc) {
	368	*outioc = NULL;
	369	}
	370	if (tlscreds && !outioc) {
	371	error_setg(errp, "Output I/O channel required for TLS");
	372	goto fail;
	373	}
	374
1c778ef7	375	if (read_sync(ioc, buf, 8) != 8) {
798bfe00 FZ	376	error_setg(errp, "Failed to read data");
	377	goto fail;
	378	}
	379
	380	buf[8] = '\0';
	381	if (strlen(buf) == 0) {
	382	error_setg(errp, "Server connection closed unexpectedly");
	383	goto fail;
	384	}
	385
	386	TRACE("Magic is %c%c%c%c%c%c%c%c",
	387	qemu_isprint(buf[0]) ? buf[0] : '.',
	388	qemu_isprint(buf[1]) ? buf[1] : '.',
	389	qemu_isprint(buf[2]) ? buf[2] : '.',
	390	qemu_isprint(buf[3]) ? buf[3] : '.',
	391	qemu_isprint(buf[4]) ? buf[4] : '.',
	392	qemu_isprint(buf[5]) ? buf[5] : '.',
	393	qemu_isprint(buf[6]) ? buf[6] : '.',
	394	qemu_isprint(buf[7]) ? buf[7] : '.');
	395
	396	if (memcmp(buf, "NBDMAGIC", 8) != 0) {
	397	error_setg(errp, "Invalid magic received");
	398	goto fail;
	399	}
	400
1c778ef7	401	if (read_sync(ioc, &magic, sizeof(magic)) != sizeof(magic)) {
798bfe00 FZ	402	error_setg(errp, "Failed to read magic");
	403	goto fail;
	404	}
	405	magic = be64_to_cpu(magic);
	406	TRACE("Magic is 0x%" PRIx64, magic);
	407
f72d705f	408	if (magic == NBD_OPTS_MAGIC) {
e2a9d9a3	409	uint32_t clientflags = 0;
798bfe00 FZ	410	uint32_t opt;
798bfe00 FZ	411	uint32_t namesize;
e2a9d9a3 DB	412	uint16_t globalflags;
e2a9d9a3 DB	413	uint16_t exportflags;
9344e5f5	414	bool fixedNewStyle = false;
798bfe00	415
e2a9d9a3 DB	416	if (read_sync(ioc, &globalflags, sizeof(globalflags)) !=
e2a9d9a3 DB	417	sizeof(globalflags)) {
798bfe00 FZ	418	error_setg(errp, "Failed to read server flags");
	419	goto fail;
	420	}
9344e5f5 DB	421	globalflags = be16_to_cpu(globalflags);
	422	*flags = globalflags << 16;
	423	TRACE("Global flags are %x", globalflags);
e2a9d9a3	424	if (globalflags & NBD_FLAG_FIXED_NEWSTYLE) {
9344e5f5	425	fixedNewStyle = true;
e2a9d9a3 DB	426	TRACE("Server supports fixed new style");
	427	clientflags \|= NBD_FLAG_C_FIXED_NEWSTYLE;
	428	}
	429	/* client requested flags */
9344e5f5	430	clientflags = cpu_to_be32(clientflags);
e2a9d9a3 DB	431	if (write_sync(ioc, &clientflags, sizeof(clientflags)) !=
	432	sizeof(clientflags)) {
	433	error_setg(errp, "Failed to send clientflags field");
798bfe00 FZ	434	goto fail;
798bfe00 FZ	435	}
f95910fe DB	436	if (tlscreds) {
	437	if (fixedNewStyle) {
	438	*outioc = nbd_receive_starttls(ioc, tlscreds, hostname, errp);
	439	if (!*outioc) {
	440	goto fail;
	441	}
	442	ioc = *outioc;
	443	} else {
	444	error_setg(errp, "Server does not support STARTTLS");
	445	goto fail;
	446	}
	447	}
f72d705f	448	if (!name) {
69b49502 DB	449	TRACE("Using default NBD export name \"\"");
69b49502 DB	450	name = "";
f72d705f	451	}
9344e5f5 DB	452	if (fixedNewStyle) {
	453	/* Check our desired export is present in the
	454	* server export list. Since NBD_OPT_EXPORT_NAME
	455	* cannot return an error message, running this
	456	* query gives us good error reporting if the
	457	* server required TLS
	458	*/
	459	if (nbd_receive_query_exports(ioc, name, errp) < 0) {
	460	goto fail;
	461	}
	462	}
	463	/* write the export name */
798bfe00	464	magic = cpu_to_be64(magic);
1c778ef7	465	if (write_sync(ioc, &magic, sizeof(magic)) != sizeof(magic)) {
798bfe00 FZ	466	error_setg(errp, "Failed to send export name magic");
	467	goto fail;
	468	}
	469	opt = cpu_to_be32(NBD_OPT_EXPORT_NAME);
1c778ef7	470	if (write_sync(ioc, &opt, sizeof(opt)) != sizeof(opt)) {
798bfe00 FZ	471	error_setg(errp, "Failed to send export name option number");
	472	goto fail;
	473	}
	474	namesize = cpu_to_be32(strlen(name));
1c778ef7	475	if (write_sync(ioc, &namesize, sizeof(namesize)) !=
798bfe00 FZ	476	sizeof(namesize)) {
	477	error_setg(errp, "Failed to send export name length");
	478	goto fail;
	479	}
1c778ef7	480	if (write_sync(ioc, (char *)name, strlen(name)) != strlen(name)) {
798bfe00 FZ	481	error_setg(errp, "Failed to send export name");
	482	goto fail;
	483	}
f72d705f DB	484
	485	if (read_sync(ioc, &s, sizeof(s)) != sizeof(s)) {
	486	error_setg(errp, "Failed to read export length");
798bfe00 FZ	487	goto fail;
798bfe00 FZ	488	}
f72d705f DB	489	*size = be64_to_cpu(s);
f72d705f DB	490	TRACE("Size is %" PRIu64, *size);
798bfe00	491
e2a9d9a3 DB	492	if (read_sync(ioc, &exportflags, sizeof(exportflags)) !=
e2a9d9a3 DB	493	sizeof(exportflags)) {
f72d705f DB	494	error_setg(errp, "Failed to read export flags");
	495	goto fail;
	496	}
9344e5f5 DB	497	exportflags = be16_to_cpu(exportflags);
	498	*flags \|= exportflags;
	499	TRACE("Export flags are %x", exportflags);
f72d705f DB	500	} else if (magic == NBD_CLIENT_MAGIC) {
	501	if (name) {
	502	error_setg(errp, "Server does not support export names");
	503	goto fail;
	504	}
f95910fe DB	505	if (tlscreds) {
	506	error_setg(errp, "Server does not support STARTTLS");
	507	goto fail;
	508	}
f72d705f DB	509
	510	if (read_sync(ioc, &s, sizeof(s)) != sizeof(s)) {
	511	error_setg(errp, "Failed to read export length");
	512	goto fail;
	513	}
	514	*size = be64_to_cpu(s);
	515	TRACE("Size is %" PRIu64, *size);
798bfe00	516
1c778ef7	517	if (read_sync(ioc, flags, sizeof(flags)) != sizeof(flags)) {
798bfe00 FZ	518	error_setg(errp, "Failed to read export flags");
	519	goto fail;
	520	}
	521	*flags = be32_to_cpup(flags);
	522	} else {
f72d705f DB	523	error_setg(errp, "Bad magic received");
f72d705f DB	524	goto fail;
798bfe00	525	}
f72d705f	526
1c778ef7	527	if (read_sync(ioc, &buf, 124) != 124) {
798bfe00 FZ	528	error_setg(errp, "Failed to read reserved block");
	529	goto fail;
	530	}
	531	rc = 0;
	532
	533	fail:
	534	return rc;
	535	}
	536
	537	#ifdef __linux__
1c778ef7	538	int nbd_init(int fd, QIOChannelSocket *sioc, uint32_t flags, off_t size)
798bfe00 FZ	539	{
	540	TRACE("Setting NBD socket");
	541
1c778ef7	542	if (ioctl(fd, NBD_SET_SOCK, sioc->fd) < 0) {
798bfe00 FZ	543	int serrno = errno;
	544	LOG("Failed to set NBD socket");
	545	return -serrno;
	546	}
	547
	548	TRACE("Setting block size to %lu", (unsigned long)BDRV_SECTOR_SIZE);
	549
	550	if (ioctl(fd, NBD_SET_BLKSIZE, (size_t)BDRV_SECTOR_SIZE) < 0) {
	551	int serrno = errno;
	552	LOG("Failed setting NBD block size");
	553	return -serrno;
	554	}
	555
	556	TRACE("Setting size to %zd block(s)", (size_t)(size / BDRV_SECTOR_SIZE));
	557
	558	if (ioctl(fd, NBD_SET_SIZE_BLOCKS, (size_t)(size / BDRV_SECTOR_SIZE)) < 0) {
	559	int serrno = errno;
	560	LOG("Failed setting size (in blocks)");
	561	return -serrno;
	562	}
	563
	564	if (ioctl(fd, NBD_SET_FLAGS, flags) < 0) {
	565	if (errno == ENOTTY) {
	566	int read_only = (flags & NBD_FLAG_READ_ONLY) != 0;
	567	TRACE("Setting readonly attribute");
	568
	569	if (ioctl(fd, BLKROSET, (unsigned long) &read_only) < 0) {
	570	int serrno = errno;
	571	LOG("Failed setting read-only attribute");
	572	return -serrno;
	573	}
	574	} else {
	575	int serrno = errno;
	576	LOG("Failed setting flags");
	577	return -serrno;
	578	}
	579	}
	580
	581	TRACE("Negotiation ended");
	582
	583	return 0;
	584	}
	585
	586	int nbd_client(int fd)
	587	{
	588	int ret;
	589	int serrno;
	590
	591	TRACE("Doing NBD loop");
	592
	593	ret = ioctl(fd, NBD_DO_IT);
	594	if (ret < 0 && errno == EPIPE) {
	595	/* NBD_DO_IT normally returns EPIPE when someone has disconnected
	596	* the socket via NBD_DISCONNECT. We do not want to return 1 in
	597	* that case.
	598	*/
	599	ret = 0;
	600	}
	601	serrno = errno;
	602
	603	TRACE("NBD loop returned %d: %s", ret, strerror(serrno));
	604
	605	TRACE("Clearing NBD queue");
	606	ioctl(fd, NBD_CLEAR_QUE);
607
608	TRACE("Clearing NBD socket");
609	ioctl(fd, NBD_CLEAR_SOCK);
610
611	errno = serrno;
612	return ret;
613	}
614	#else
1c778ef7	615	int nbd_init(int fd, QIOChannelSocket *ioc, uint32_t flags, off_t size)
798bfe00 FZ	616	{
	617	return -ENOTSUP;
	618	}
	619
	620	int nbd_client(int fd)
	621	{
	622	return -ENOTSUP;
	623	}
	624	#endif
	625
1c778ef7	626	ssize_t nbd_send_request(QIOChannel ioc, struct nbd_request request)
798bfe00 FZ	627	{
	628	uint8_t buf[NBD_REQUEST_SIZE];
	629	ssize_t ret;
	630
	631	cpu_to_be32w((uint32_t*)buf, NBD_REQUEST_MAGIC);
	632	cpu_to_be32w((uint32_t*)(buf + 4), request->type);
	633	cpu_to_be64w((uint64_t*)(buf + 8), request->handle);
	634	cpu_to_be64w((uint64_t*)(buf + 16), request->from);
	635	cpu_to_be32w((uint32_t*)(buf + 24), request->len);
	636
b6afc654	637	TRACE("Sending request to server: "
798bfe00 FZ	638	"{ .from = %" PRIu64", .len = %u, .handle = %" PRIu64", .type=%i}",
	639	request->from, request->len, request->handle, request->type);
	640
1c778ef7	641	ret = write_sync(ioc, buf, sizeof(buf));
798bfe00 FZ	642	if (ret < 0) {
	643	return ret;
	644	}
	645
	646	if (ret != sizeof(buf)) {
	647	LOG("writing to socket failed");
	648	return -EINVAL;
	649	}
	650	return 0;
	651	}
	652
1c778ef7	653	ssize_t nbd_receive_reply(QIOChannel ioc, struct nbd_reply reply)
798bfe00 FZ	654	{
	655	uint8_t buf[NBD_REPLY_SIZE];
	656	uint32_t magic;
	657	ssize_t ret;
	658
1c778ef7	659	ret = read_sync(ioc, buf, sizeof(buf));
798bfe00 FZ	660	if (ret < 0) {
	661	return ret;
	662	}
	663
	664	if (ret != sizeof(buf)) {
	665	LOG("read failed");
	666	return -EINVAL;
	667	}
	668
	669	/* Reply
	670	[ 0 .. 3] magic (NBD_REPLY_MAGIC)
	671	[ 4 .. 7] error (0 == no error)
	672	[ 7 .. 15] handle
	673	*/
	674
	675	magic = be32_to_cpup((uint32_t*)buf);
	676	reply->error = be32_to_cpup((uint32_t*)(buf + 4));
	677	reply->handle = be64_to_cpup((uint64_t*)(buf + 8));
	678
	679	reply->error = nbd_errno_to_system_errno(reply->error);
	680
	681	TRACE("Got reply: "
	682	"{ magic = 0x%x, .error = %d, handle = %" PRIu64" }",
	683	magic, reply->error, reply->handle);
	684
	685	if (magic != NBD_REPLY_MAGIC) {
	686	LOG("invalid magic (got 0x%x)", magic);
	687	return -EINVAL;
	688	}
	689	return 0;
	690	}
	691