X-Git-Url: https://gerrit.opnfv.org/gerrit/gitweb?a=blobdiff_plain;f=qemu%2Fnbd%2Fclient.c;fp=qemu%2Fnbd%2Fclient.c;h=48f2a21f3387ee72bd01c9932c2cfa7c867f8c87;hb=437fd90c0250dee670290f9b714253671a990160;hp=0000000000000000000000000000000000000000;hpb=5bbd6fe9b8bab2a93e548c5a53b032d1939eec05;p=kvmfornfv.git

diff --git a/qemu/nbd/client.c b/qemu/nbd/client.c
new file mode 100644
index 000000000..48f2a21f3
--- /dev/null
+++ b/qemu/nbd/client.c
@@ -0,0 +1,745 @@
+/*
+ *  Copyright (C) 2005  Anthony Liguori <anthony@codemonkey.ws>
+ *
+ *  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)
+
+*/
+
+
+/* If type represents success, return 1 without further action.
+ * If type represents an error reply, consume the rest of the packet on ioc.
+ * Then return 0 for unsupported (so the client can fall back to
+ * other approaches), or -1 with errp set for other errors.
+ */
+static int nbd_handle_reply_err(QIOChannel *ioc, uint32_t opt, uint32_t type,
+                                Error **errp)
+{
+    uint32_t len;
+    char *msg = NULL;
+    int result = -1;
+
+    if (!(type & (1 << 31))) {
+        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 (len) {
+        if (len > NBD_MAX_BUFFER_SIZE) {
+            error_setg(errp, "server's error message is too long");
+            goto cleanup;
+        }
+        msg = g_malloc(len + 1);
+        if (read_sync(ioc, msg, len) != len) {
+            error_setg(errp, "failed to read option error message");
+            goto cleanup;
+        }
+        msg[len] = '\0';
+    }
+
+    switch (type) {
+    case NBD_REP_ERR_UNSUP:
+        TRACE("server doesn't understand request %d, attempting fallback",
+              opt);
+        result = 0;
+        goto cleanup;
+
+    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;
+    }
+
+    if (msg) {
+        error_append_hint(errp, "%s\n", msg);
+    }
+
+ cleanup:
+    g_free(msg);
+    return result;
+}
+
+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;
+    int error;
+
+    *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);
+    error = nbd_handle_reply_err(ioc, opt, type, errp);
+    if (error <= 0) {
+        return error;
+    }
+
+    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 (len < sizeof(namelen) || len > NBD_MAX_BUFFER_SIZE) {
+            error_setg(errp, "incorrect option length");
+            return -1;
+        }
+        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);
+        len -= sizeof(namelen);
+        if (len < namelen) {
+            error_setg(errp, "incorrect option name 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';
+        len -= namelen;
+        if (len) {
+            char *buf = g_malloc(len + 1);
+            if (read_sync(ioc, buf, len) != len) {
+                error_setg(errp, "failed to read export description");
+                g_free(*name);
+                g_free(buf);
+                *name = NULL;
+                return -1;
+            }
+            buf[len] = '\0';
+            TRACE("Ignoring export description: %s", buf);
+            g_free(buf);
+        }
+    } 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;
+
+    TRACE("Sending request to server: "
+          "{ .from = %" PRIu64", .len = %u, .handle = %" PRIu64", .type=%i}",
+          request->from, request->len, request->handle, request->type);
+
+    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);
+
+    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;
+}
+