--- /dev/null
+/*
+ * 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;
+}
+
Code Review / kvmfornfv.git / blobdiff