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: Eric Blake <eblake@redhat.com>
Reviewed-by: Richard W.M. Jones <rjones@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20190117193658.16413-14-eblake@redhat.com>
This commit is contained in:
Eric Blake 2019-01-17 13:36:50 -06:00
parent 0182c1aed9
commit 2b8d095451

View file

@ -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__