Commit 2b8d0954 authored by Eric Blake's avatar Eric Blake
Browse files

nbd/client: Refactor return of nbd_receive_negotiate() 



The function could only ever return 0 or -EINVAL; make this
clearer by dropping a useless 'fail:' label.

Signed-off-by: default avatarEric Blake <eblake@redhat.com>
Reviewed-by: default avatarRichard W.M. Jones <rjones@redhat.com>
Reviewed-by: default avatarVladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20190117193658.16413-14-eblake@redhat.com>
parent 0182c1ae

nbd/client.c

+23 −28
Original line number Diff line number Diff line
@@ -814,7 +814,6 @@ int nbd_receive_negotiate(QIOChannel *ioc, QCryptoTLSCreds *tlscreds, 
                          NBDExportInfo *info, Error **errp)

{

    uint64_t magic;

    int rc;

    bool zeroes = true;

    bool structured_reply = info->structured_reply;

    bool base_allocation = info->base_allocation;
@@ -825,31 +824,30 @@ int nbd_receive_negotiate(QIOChannel *ioc, QCryptoTLSCreds *tlscreds, 
    trace_nbd_receive_negotiate_name(info->name);

    info->structured_reply = false;

    info->base_allocation = false;

    rc = -EINVAL;



    if (outioc) {

        *outioc = NULL;

    }

    if (tlscreds && !outioc) {

        error_setg(errp, "Output I/O channel required for TLS");

        goto fail;

        return -EINVAL;

    }



    if (nbd_read(ioc, &magic, sizeof(magic), errp) < 0) {

        error_prepend(errp, "Failed to read initial magic: ");

        goto fail;

        return -EINVAL;

    }

    magic = be64_to_cpu(magic);

    trace_nbd_receive_negotiate_magic(magic);



    if (magic != NBD_INIT_MAGIC) {

        error_setg(errp, "Bad initial magic received: 0x%" PRIx64, magic);

        goto fail;

        return -EINVAL;

    }



    if (nbd_read(ioc, &magic, sizeof(magic), errp) < 0) {

        error_prepend(errp, "Failed to read server magic: ");

        goto fail;

        return -EINVAL;

    }

    magic = be64_to_cpu(magic);

    trace_nbd_receive_negotiate_magic(magic);
@@ -861,7 +859,7 @@ int nbd_receive_negotiate(QIOChannel *ioc, QCryptoTLSCreds *tlscreds, 


        if (nbd_read(ioc, &globalflags, sizeof(globalflags), errp) < 0) {

            error_prepend(errp, "Failed to read server flags: ");

            goto fail;

            return -EINVAL;

        }

        globalflags = be16_to_cpu(globalflags);

        trace_nbd_receive_negotiate_server_flags(globalflags);
@@ -877,18 +875,18 @@ int nbd_receive_negotiate(QIOChannel *ioc, QCryptoTLSCreds *tlscreds, 
        clientflags = cpu_to_be32(clientflags);

        if (nbd_write(ioc, &clientflags, sizeof(clientflags), errp) < 0) {

            error_prepend(errp, "Failed to send clientflags field: ");

            goto fail;

            return -EINVAL;

        }

        if (tlscreds) {

            if (fixedNewStyle) {

                *outioc = nbd_receive_starttls(ioc, tlscreds, hostname, errp);

                if (!*outioc) {

                    goto fail;

                    return -EINVAL;

                }

                ioc = *outioc;

            } else {

                error_setg(errp, "Server does not support STARTTLS");

                goto fail;

                return -EINVAL;

            }

        }

        if (fixedNewStyle) {
@@ -899,7 +897,7 @@ int nbd_receive_negotiate(QIOChannel *ioc, QCryptoTLSCreds *tlscreds, 
                                                   NBD_OPT_STRUCTURED_REPLY,

                                                   errp);

                if (result < 0) {

                    goto fail;

                    return -EINVAL;

                }

                info->structured_reply = result == 1;

            }
@@ -907,7 +905,7 @@ int nbd_receive_negotiate(QIOChannel *ioc, QCryptoTLSCreds *tlscreds, 
            if (info->structured_reply && base_allocation) {

                result = nbd_negotiate_simple_meta_context(ioc, info, errp);

                if (result < 0) {

                    goto fail;

                    return -EINVAL;

                }

                info->base_allocation = result == 1;

            }
@@ -919,7 +917,7 @@ int nbd_receive_negotiate(QIOChannel *ioc, QCryptoTLSCreds *tlscreds, 
             * export, then use NBD_OPT_EXPORT_NAME.  */

            result = nbd_opt_go(ioc, info, errp);

            if (result < 0) {

                goto fail;

                return -EINVAL;

            }

            if (result > 0) {

                return 0;
@@ -931,25 +929,25 @@ int nbd_receive_negotiate(QIOChannel *ioc, QCryptoTLSCreds *tlscreds, 
             * export name is not available.

             */

            if (nbd_receive_query_exports(ioc, info->name, errp) < 0) {

                goto fail;

                return -EINVAL;

            }

        }

        /* write the export name request */

        if (nbd_send_option_request(ioc, NBD_OPT_EXPORT_NAME, -1, info->name,

                                    errp) < 0) {

            goto fail;

            return -EINVAL;

        }



        /* Read the response */

        if (nbd_read(ioc, &info->size, sizeof(info->size), errp) < 0) {

            error_prepend(errp, "Failed to read export length: ");

            goto fail;

            return -EINVAL;

        }

        info->size = be64_to_cpu(info->size);



        if (nbd_read(ioc, &info->flags, sizeof(info->flags), errp) < 0) {

            error_prepend(errp, "Failed to read export flags: ");

            goto fail;

            return -EINVAL;

        }

        info->flags = be16_to_cpu(info->flags);

    } else if (magic == NBD_CLIENT_MAGIC) {
@@ -957,43 +955,40 @@ int nbd_receive_negotiate(QIOChannel *ioc, QCryptoTLSCreds *tlscreds, 


        if (*info->name) {

            error_setg(errp, "Server does not support non-empty export names");

            goto fail;

            return -EINVAL;

        }

        if (tlscreds) {

            error_setg(errp, "Server does not support STARTTLS");

            goto fail;

            return -EINVAL;

        }



        if (nbd_read(ioc, &info->size, sizeof(info->size), errp) < 0) {

            error_prepend(errp, "Failed to read export length: ");

            goto fail;

            return -EINVAL;

        }

        info->size = be64_to_cpu(info->size);



        if (nbd_read(ioc, &oldflags, sizeof(oldflags), errp) < 0) {

            error_prepend(errp, "Failed to read export flags: ");

            goto fail;

            return -EINVAL;

        }

        oldflags = be32_to_cpu(oldflags);

        if (oldflags & ~0xffff) {

            error_setg(errp, "Unexpected export flags %0x" PRIx32, oldflags);

            goto fail;

            return -EINVAL;

        }

        info->flags = oldflags;

    } else {

        error_setg(errp, "Bad server magic received: 0x%" PRIx64, magic);

        goto fail;

        return -EINVAL;

    }



    trace_nbd_receive_negotiate_size_flags(info->size, info->flags);

    if (zeroes && nbd_drop(ioc, 124, errp) < 0) {

        error_prepend(errp, "Failed to read reserved block: ");

        goto fail;

        return -EINVAL;

    }

    rc = 0;



fail:

    return rc;

    return 0;

}



#ifdef __linux__