/*
+ * Copyright (C) 2016 Red Hat, Inc.
*
* Network Block Device Client Side
return ENOMEM;
case NBD_ENOSPC:
return ENOSPC;
- case NBD_EINVAL:
default:
+ TRACE("Squashing unexpected error %d to EINVAL", err);
+ /* fallthrough */
+ case NBD_EINVAL:
return EINVAL;
}
}
*/
+/* Discard length bytes from channel. Return -errno on failure, or
+ * the amount of bytes consumed. */
+static ssize_t drop_sync(QIOChannel *ioc, size_t size)
+{
+ ssize_t ret, dropped = size;
+ char small[1024];
+ char *buffer;
-static int nbd_handle_reply_err(uint32_t opt, uint32_t type, Error **errp)
+ buffer = sizeof(small) < size ? small : g_malloc(MIN(65536, size));
+ while (size > 0) {
+ ret = read_sync(ioc, buffer, MIN(65536, size));
+ if (ret < 0) {
+ goto cleanup;
+ }
+ assert(ret <= size);
+ size -= ret;
+ }
+ ret = dropped;
+
+ cleanup:
+ if (buffer != small) {
+ g_free(buffer);
+ }
+ return ret;
+}
+
+/* Send an option request.
+ *
+ * The request is for option @opt, with @data containing @len bytes of
+ * additional payload for the request (@len may be -1 to treat @data as
+ * a C string; and @data may be NULL if @len is 0).
+ * Return 0 if successful, -1 with errp set if it is impossible to
+ * continue. */
+static int nbd_send_option_request(QIOChannel *ioc, uint32_t opt,
+ uint32_t len, const char *data,
+ Error **errp)
{
- if (!(type & (1 << 31))) {
- return 0;
+ nbd_option req;
+ QEMU_BUILD_BUG_ON(sizeof(req) != 16);
+
+ if (len == -1) {
+ req.length = len = strlen(data);
+ }
+ TRACE("Sending option request %" PRIu32", len %" PRIu32, opt, len);
+
+ stq_be_p(&req.magic, NBD_OPTS_MAGIC);
+ stl_be_p(&req.option, opt);
+ stl_be_p(&req.length, len);
+
+ if (write_sync(ioc, &req, sizeof(req)) != sizeof(req)) {
+ error_setg(errp, "Failed to send option request header");
+ return -1;
+ }
+
+ if (len && write_sync(ioc, (char *) data, len) != len) {
+ error_setg(errp, "Failed to send option request data");
+ return -1;
+ }
+
+ return 0;
+}
+
+/* Send NBD_OPT_ABORT as a courtesy to let the server know that we are
+ * not going to attempt further negotiation. */
+static void nbd_send_opt_abort(QIOChannel *ioc)
+{
+ /* Technically, a compliant server is supposed to reply to us; but
+ * older servers disconnected instead. At any rate, we're allowed
+ * to disconnect without waiting for the server reply, so we don't
+ * even care if the request makes it to the server, let alone
+ * waiting around for whether the server replies. */
+ nbd_send_option_request(ioc, NBD_OPT_ABORT, 0, NULL, NULL);
+}
+
+
+/* Receive the header of an option reply, which should match the given
+ * opt. Read through the length field, but NOT the length bytes of
+ * payload. Return 0 if successful, -1 with errp set if it is
+ * impossible to continue. */
+static int nbd_receive_option_reply(QIOChannel *ioc, uint32_t opt,
+ nbd_opt_reply *reply, Error **errp)
+{
+ QEMU_BUILD_BUG_ON(sizeof(*reply) != 20);
+ if (read_sync(ioc, reply, sizeof(*reply)) != sizeof(*reply)) {
+ error_setg(errp, "failed to read option reply");
+ nbd_send_opt_abort(ioc);
+ return -1;
+ }
+ be64_to_cpus(&reply->magic);
+ be32_to_cpus(&reply->option);
+ be32_to_cpus(&reply->type);
+ be32_to_cpus(&reply->length);
+
+ TRACE("Received option reply %" PRIx32", type %" PRIx32", len %" PRIu32,
+ reply->option, reply->type, reply->length);
+
+ if (reply->magic != NBD_REP_MAGIC) {
+ error_setg(errp, "Unexpected option reply magic");
+ nbd_send_opt_abort(ioc);
+ return -1;
+ }
+ if (reply->option != opt) {
+ error_setg(errp, "Unexpected option type %x expected %x",
+ reply->option, opt);
+ nbd_send_opt_abort(ioc);
+ return -1;
+ }
+ return 0;
+}
+
+/* If reply represents success, return 1 without further action.
+ * If reply represents an error, consume the optional payload 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, nbd_opt_reply *reply,
+ Error **errp)
+{
+ char *msg = NULL;
+ int result = -1;
+
+ if (!(reply->type & (1 << 31))) {
+ return 1;
+ }
+
+ if (reply->length) {
+ if (reply->length > NBD_MAX_BUFFER_SIZE) {
+ error_setg(errp, "server's error message is too long");
+ goto cleanup;
+ }
+ msg = g_malloc(reply->length + 1);
+ if (read_sync(ioc, msg, reply->length) != reply->length) {
+ error_setg(errp, "failed to read option error message");
+ goto cleanup;
+ }
+ msg[reply->length] = '\0';
}
- switch (type) {
+ switch (reply->type) {
case NBD_REP_ERR_UNSUP:
- error_setg(errp, "Unsupported option type %x", opt);
- break;
+ TRACE("server doesn't understand request %" PRIx32
+ ", attempting fallback", reply->option);
+ result = 0;
+ goto cleanup;
case NBD_REP_ERR_POLICY:
- error_setg(errp, "Denied by server for option %x", opt);
+ error_setg(errp, "Denied by server for option %" PRIx32,
+ reply->option);
break;
case NBD_REP_ERR_INVALID:
- error_setg(errp, "Invalid data length for option %x", opt);
+ error_setg(errp, "Invalid data length for option %" PRIx32,
+ reply->option);
break;
case NBD_REP_ERR_TLS_REQD:
- error_setg(errp, "TLS negotiation required before option %x", opt);
+ error_setg(errp, "TLS negotiation required before option %" PRIx32,
+ reply->option);
break;
default:
- error_setg(errp, "Unknown error code when asking for option %x", opt);
+ error_setg(errp, "Unknown error code when asking for option %" PRIx32,
+ reply->option);
break;
}
- return -1;
+ if (msg) {
+ error_append_hint(errp, "%s\n", msg);
+ }
+
+ cleanup:
+ g_free(msg);
+ if (result < 0) {
+ nbd_send_opt_abort(ioc);
+ }
+ return result;
}
static int nbd_receive_list(QIOChannel *ioc, char **name, Error **errp)
{
- uint64_t magic;
- uint32_t opt;
- uint32_t type;
+ nbd_opt_reply reply;
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");
+ if (nbd_receive_option_reply(ioc, NBD_OPT_LIST, &reply, errp) < 0) {
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;
+ error = nbd_handle_reply_err(ioc, &reply, errp);
+ if (error <= 0) {
+ return error;
}
+ len = reply.length;
- 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 (reply.type == NBD_REP_ACK) {
if (len != 0) {
error_setg(errp, "length too long for option end");
+ nbd_send_opt_abort(ioc);
+ return -1;
+ }
+ } else if (reply.type == NBD_REP_SERVER) {
+ if (len < sizeof(namelen) || len > NBD_MAX_BUFFER_SIZE) {
+ error_setg(errp, "incorrect option length %" PRIu32, len);
+ nbd_send_opt_abort(ioc);
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");
+ nbd_send_opt_abort(ioc);
return -1;
}
namelen = be32_to_cpu(namelen);
- if (len != (namelen + sizeof(namelen))) {
- error_setg(errp, "incorrect option mame length");
+ len -= sizeof(namelen);
+ if (len < namelen) {
+ error_setg(errp, "incorrect option name length");
+ nbd_send_opt_abort(ioc);
return -1;
}
- if (namelen > 255) {
- error_setg(errp, "export name length too long %d", namelen);
+ if (namelen > NBD_MAX_NAME_SIZE) {
+ error_setg(errp, "export name length too long %" PRIu32, namelen);
+ nbd_send_opt_abort(ioc);
return -1;
}
error_setg(errp, "failed to read export name");
g_free(*name);
*name = NULL;
+ nbd_send_opt_abort(ioc);
return -1;
}
(*name)[namelen] = '\0';
+ len -= namelen;
+ if (drop_sync(ioc, len) != len) {
+ error_setg(errp, "failed to read export description");
+ g_free(*name);
+ *name = NULL;
+ nbd_send_opt_abort(ioc);
+ return -1;
+ }
} else {
- error_setg(errp, "Unexpected reply type %x expected %x",
- type, NBD_REP_SERVER);
+ error_setg(errp, "Unexpected reply type %" PRIx32 " expected %x",
+ reply.type, NBD_REP_SERVER);
+ nbd_send_opt_abort(ioc);
return -1;
}
return 1;
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");
+ if (nbd_send_option_request(ioc, NBD_OPT_LIST, 0, NULL, errp) < 0) {
return -1;
}
if (!foundExport) {
error_setg(errp, "No export with name '%s' available", wantname);
+ nbd_send_opt_abort(ioc);
return -1;
}
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;
+ nbd_opt_reply reply;
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);
+ if (nbd_send_option_request(ioc, NBD_OPT_STARTTLS, 0, NULL, errp) < 0) {
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);
+ if (nbd_receive_option_reply(ioc, NBD_OPT_STARTTLS, &reply, errp) < 0) {
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");
+ if (reply.type != NBD_REP_ACK) {
+ error_setg(errp, "Server rejected request to start TLS %" PRIx32,
+ reply.type);
+ nbd_send_opt_abort(ioc);
return NULL;
}
- length = be32_to_cpu(length);
- if (length != 0) {
- error_setg(errp, "Start TLS reponse was not zero %x",
- length);
+
+ if (reply.length != 0) {
+ error_setg(errp, "Start TLS response was not zero %" PRIu32,
+ reply.length);
+ nbd_send_opt_abort(ioc);
return NULL;
}
if (!tioc) {
return NULL;
}
+ qio_channel_set_name(QIO_CHANNEL(tioc), "nbd-client-tls");
data.loop = g_main_loop_new(g_main_context_default(), FALSE);
- TRACE("Starting TLS hanshake");
+ TRACE("Starting TLS handshake");
qio_channel_tls_handshake(tioc,
nbd_tls_handshake,
&data,
}
-int nbd_receive_negotiate(QIOChannel *ioc, const char *name, uint32_t *flags,
+int nbd_receive_negotiate(QIOChannel *ioc, const char *name, uint16_t *flags,
QCryptoTLSCreds *tlscreds, const char *hostname,
QIOChannel **outioc,
off_t *size, Error **errp)
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)) !=
goto fail;
}
globalflags = be16_to_cpu(globalflags);
- *flags = globalflags << 16;
- TRACE("Global flags are %x", globalflags);
+ TRACE("Global flags are %" PRIx32, globalflags);
if (globalflags & NBD_FLAG_FIXED_NEWSTYLE) {
fixedNewStyle = true;
TRACE("Server supports fixed new style");
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");
+ /* write the export name request */
+ if (nbd_send_option_request(ioc, NBD_OPT_EXPORT_NAME, -1, name,
+ errp) < 0) {
goto fail;
}
+ /* Read the response */
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)) {
+ if (read_sync(ioc, flags, sizeof(*flags)) != sizeof(*flags)) {
error_setg(errp, "Failed to read export flags");
goto fail;
}
- exportflags = be16_to_cpu(exportflags);
- *flags |= exportflags;
- TRACE("Export flags are %x", exportflags);
+ be16_to_cpus(flags);
} else if (magic == NBD_CLIENT_MAGIC) {
+ uint32_t oldflags;
+
if (name) {
error_setg(errp, "Server does not support export names");
goto fail;
*size = be64_to_cpu(s);
TRACE("Size is %" PRIu64, *size);
- if (read_sync(ioc, flags, sizeof(*flags)) != sizeof(*flags)) {
+ if (read_sync(ioc, &oldflags, sizeof(oldflags)) != sizeof(oldflags)) {
error_setg(errp, "Failed to read export flags");
goto fail;
}
- *flags = be32_to_cpup(flags);
+ be32_to_cpus(&oldflags);
+ if (oldflags & ~0xffff) {
+ error_setg(errp, "Unexpected export flags %0x" PRIx32, oldflags);
+ goto fail;
+ }
+ *flags = oldflags;
} else {
error_setg(errp, "Bad magic received");
goto fail;
}
- if (read_sync(ioc, &buf, 124) != 124) {
+ TRACE("Size is %" PRIu64 ", export flags %" PRIx16, *size, *flags);
+ if (drop_sync(ioc, 124) != 124) {
error_setg(errp, "Failed to read reserved block");
goto fail;
}
}
#ifdef __linux__
-int nbd_init(int fd, QIOChannelSocket *sioc, uint32_t flags, off_t size)
+int nbd_init(int fd, QIOChannelSocket *sioc, uint16_t flags, off_t size)
{
+ unsigned long sectors = size / BDRV_SECTOR_SIZE;
+ if (size / BDRV_SECTOR_SIZE != sectors) {
+ LOG("Export size %lld too large for 32-bit kernel", (long long) size);
+ return -E2BIG;
+ }
+
TRACE("Setting NBD socket");
- if (ioctl(fd, NBD_SET_SOCK, sioc->fd) < 0) {
+ if (ioctl(fd, NBD_SET_SOCK, (unsigned long) 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) {
+ if (ioctl(fd, NBD_SET_BLKSIZE, (unsigned long)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));
+ TRACE("Setting size to %lu block(s)", sectors);
+ if (size % BDRV_SECTOR_SIZE) {
+ TRACE("Ignoring trailing %d bytes of export",
+ (int) (size % BDRV_SECTOR_SIZE));
+ }
- if (ioctl(fd, NBD_SET_SIZE_BLOCKS, (size_t)(size / BDRV_SECTOR_SIZE)) < 0) {
+ if (ioctl(fd, NBD_SET_SIZE_BLOCKS, sectors) < 0) {
int serrno = errno;
LOG("Failed setting size (in blocks)");
return -serrno;
}
- if (ioctl(fd, NBD_SET_FLAGS, flags) < 0) {
+ if (ioctl(fd, NBD_SET_FLAGS, (unsigned long) flags) < 0) {
if (errno == ENOTTY) {
int read_only = (flags & NBD_FLAG_READ_ONLY) != 0;
TRACE("Setting readonly attribute");
errno = serrno;
return ret;
}
+
+int nbd_disconnect(int fd)
+{
+ ioctl(fd, NBD_CLEAR_QUE);
+ ioctl(fd, NBD_DISCONNECT);
+ ioctl(fd, NBD_CLEAR_SOCK);
+ return 0;
+}
+
#else
-int nbd_init(int fd, QIOChannelSocket *ioc, uint32_t flags, off_t size)
+int nbd_init(int fd, QIOChannelSocket *ioc, uint16_t flags, off_t size)
{
return -ENOTSUP;
}
{
return -ENOTSUP;
}
+int nbd_disconnect(int fd)
+{
+ return -ENOTSUP;
+}
#endif
-ssize_t nbd_send_request(QIOChannel *ioc, struct nbd_request *request)
+ssize_t nbd_send_request(QIOChannel *ioc, NBDRequest *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 = %" PRIu32 ", .handle = %" PRIu64
+ ", .flags = %" PRIx16 ", .type = %" PRIu16 " }",
+ request->from, request->len, request->handle,
+ request->flags, request->type);
- TRACE("Sending request to client: "
- "{ .from = %" PRIu64", .len = %u, .handle = %" PRIu64", .type=%i}",
- request->from, request->len, request->handle, request->type);
+ stl_be_p(buf, NBD_REQUEST_MAGIC);
+ stw_be_p(buf + 4, request->flags);
+ stw_be_p(buf + 6, request->type);
+ stq_be_p(buf + 8, request->handle);
+ stq_be_p(buf + 16, request->from);
+ stl_be_p(buf + 24, request->len);
ret = write_sync(ioc, buf, sizeof(buf));
if (ret < 0) {
return 0;
}
-ssize_t nbd_receive_reply(QIOChannel *ioc, struct nbd_reply *reply)
+ssize_t nbd_receive_reply(QIOChannel *ioc, NBDReply *reply)
{
uint8_t buf[NBD_REPLY_SIZE];
uint32_t magic;
[ 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));
+ magic = ldl_be_p(buf);
+ reply->error = ldl_be_p(buf + 4);
+ reply->handle = ldq_be_p(buf + 8);
reply->error = nbd_errno_to_system_errno(reply->error);
- TRACE("Got reply: "
- "{ magic = 0x%x, .error = %d, handle = %" PRIu64" }",
+ TRACE("Got reply: { magic = 0x%" PRIx32 ", .error = % " PRId32
+ ", handle = %" PRIu64" }",
magic, reply->error, reply->handle);
if (magic != NBD_REPLY_MAGIC) {
- LOG("invalid magic (got 0x%x)", magic);
+ LOG("invalid magic (got 0x%" PRIx32 ")", magic);
return -EINVAL;
}
return 0;
projects / qemu.git / blobdiff