/*
+ * Copyright (C) 2016-2017 Red Hat, Inc.
*
* Network Block Device Client Side
#include "qemu/osdep.h"
#include "qapi/error.h"
+#include "trace.h"
#include "nbd-internal.h"
static int nbd_errno_to_system_errno(int err)
{
+ int ret;
switch (err) {
case NBD_SUCCESS:
- return 0;
+ ret = 0;
+ break;
case NBD_EPERM:
- return EPERM;
+ ret = EPERM;
+ break;
case NBD_EIO:
- return EIO;
+ ret = EIO;
+ break;
case NBD_ENOMEM:
- return ENOMEM;
+ ret = ENOMEM;
+ break;
case NBD_ENOSPC:
- return ENOSPC;
+ ret = ENOSPC;
+ break;
+ case NBD_ESHUTDOWN:
+ ret = ESHUTDOWN;
+ break;
default:
- TRACE("Squashing unexpected error %d to EINVAL", err);
+ trace_nbd_unknown_error(err);
/* fallthrough */
case NBD_EINVAL:
- return EINVAL;
+ ret = EINVAL;
+ break;
}
+ return ret;
}
/* Definitions for opaque data types */
*/
+/* 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)
+{
+ nbd_option req;
+ QEMU_BUILD_BUG_ON(sizeof(req) != 16);
+
+ if (len == -1) {
+ req.length = len = strlen(data);
+ }
+ trace_nbd_send_option_request(opt, nbd_opt_lookup(opt), len);
+
+ stq_be_p(&req.magic, NBD_OPTS_MAGIC);
+ stl_be_p(&req.option, opt);
+ stl_be_p(&req.length, len);
+
+ if (nbd_write(ioc, &req, sizeof(req), errp) < 0) {
+ error_prepend(errp, "Failed to send option request header");
+ return -1;
+ }
+
+ if (len && nbd_write(ioc, (char *) data, len, errp) < 0) {
+ error_prepend(errp, "Failed to send option request data");
+ return -1;
+ }
-/* 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.
+ 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 (nbd_read(ioc, reply, sizeof(*reply), errp) < 0) {
+ error_prepend(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_nbd_receive_option_reply(reply->option, nbd_opt_lookup(reply->option),
+ reply->type, nbd_rep_lookup(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, uint32_t opt, uint32_t type,
+static int nbd_handle_reply_err(QIOChannel *ioc, nbd_opt_reply *reply,
Error **errp)
{
- uint32_t len;
char *msg = NULL;
int result = -1;
- if (!(type & (1 << 31))) {
+ if (!(reply->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");
+ if (reply->length) {
+ if (reply->length > NBD_MAX_BUFFER_SIZE) {
+ error_setg(errp, "server error 0x%" PRIx32
+ " (%s) message is too long",
+ reply->type, nbd_rep_lookup(reply->type));
goto cleanup;
}
- msg = g_malloc(len + 1);
- if (read_sync(ioc, msg, len) != len) {
- error_setg(errp, "failed to read option error message");
+ msg = g_malloc(reply->length + 1);
+ if (nbd_read(ioc, msg, reply->length, errp) < 0) {
+ error_prepend(errp, "failed to read option error 0x%" PRIx32
+ " (%s) message",
+ reply->type, nbd_rep_lookup(reply->type));
goto cleanup;
}
- msg[len] = '\0';
+ msg[reply->length] = '\0';
}
- switch (type) {
+ switch (reply->type) {
case NBD_REP_ERR_UNSUP:
- TRACE("server doesn't understand request %" PRIx32
- ", attempting fallback", opt);
+ trace_nbd_reply_err_unsup(reply->option, nbd_opt_lookup(reply->option));
result = 0;
goto cleanup;
case NBD_REP_ERR_POLICY:
- error_setg(errp, "Denied by server for option %" PRIx32, opt);
+ error_setg(errp, "Denied by server for option %" PRIx32 " (%s)",
+ reply->option, nbd_opt_lookup(reply->option));
break;
case NBD_REP_ERR_INVALID:
- error_setg(errp, "Invalid data length for option %" PRIx32, opt);
+ error_setg(errp, "Invalid data length for option %" PRIx32 " (%s)",
+ reply->option, nbd_opt_lookup(reply->option));
+ break;
+
+ case NBD_REP_ERR_PLATFORM:
+ error_setg(errp, "Server lacks support for option %" PRIx32 " (%s)",
+ reply->option, nbd_opt_lookup(reply->option));
break;
case NBD_REP_ERR_TLS_REQD:
- error_setg(errp, "TLS negotiation required before option %" PRIx32,
- opt);
+ error_setg(errp, "TLS negotiation required before option %" PRIx32
+ " (%s)", reply->option, nbd_opt_lookup(reply->option));
+ break;
+
+ case NBD_REP_ERR_UNKNOWN:
+ error_setg(errp, "Requested export not available");
+ break;
+
+ case NBD_REP_ERR_SHUTDOWN:
+ error_setg(errp, "Server shutting down before option %" PRIx32 " (%s)",
+ reply->option, nbd_opt_lookup(reply->option));
+ break;
+
+ case NBD_REP_ERR_BLOCK_SIZE_REQD:
+ error_setg(errp, "Server requires INFO_BLOCK_SIZE for option %" PRIx32
+ " (%s)", reply->option, nbd_opt_lookup(reply->option));
break;
default:
- error_setg(errp, "Unknown error code when asking for option %" PRIx32,
- opt);
+ error_setg(errp, "Unknown error code when asking for option %" PRIx32
+ " (%s)", reply->option, nbd_opt_lookup(reply->option));
break;
}
if (msg) {
- error_append_hint(errp, "%s\n", msg);
+ error_append_hint(errp, "server reported: %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)
+/* Process another portion of the NBD_OPT_LIST reply. Set *@match if
+ * the current reply matches @want or if the server does not support
+ * NBD_OPT_LIST, otherwise leave @match alone. Return 0 if iteration
+ * is complete, positive if more replies are expected, or negative
+ * with @errp set if an unrecoverable error occurred. */
+static int nbd_receive_list(QIOChannel *ioc, const char *want, bool *match,
+ Error **errp)
{
- uint64_t magic;
- uint32_t opt;
- uint32_t type;
+ nbd_opt_reply reply;
uint32_t len;
uint32_t namelen;
+ char name[NBD_MAX_NAME_SIZE + 1];
int error;
- *name = NULL;
- if (read_sync(ioc, &magic, sizeof(magic)) != sizeof(magic)) {
- error_setg(errp, "failed to read list option magic");
+ if (nbd_receive_option_reply(ioc, NBD_OPT_LIST, &reply, errp) < 0) {
return -1;
}
- magic = be64_to_cpu(magic);
- if (magic != NBD_REP_MAGIC) {
- error_setg(errp, "Unexpected option list magic");
+ error = nbd_handle_reply_err(ioc, &reply, errp);
+ if (error <= 0) {
+ /* The server did not support NBD_OPT_LIST, so set *match on
+ * the assumption that any name will be accepted. */
+ *match = true;
+ return error;
+ }
+ len = reply.length;
+
+ 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;
+ }
+ return 0;
+ } else if (reply.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;
}
- if (read_sync(ioc, &opt, sizeof(opt)) != sizeof(opt)) {
- error_setg(errp, "failed to read list option");
+
+ if (len < sizeof(namelen) || len > NBD_MAX_BUFFER_SIZE) {
+ error_setg(errp, "incorrect option length %" PRIu32, len);
+ nbd_send_opt_abort(ioc);
+ return -1;
+ }
+ if (nbd_read(ioc, &namelen, sizeof(namelen), errp) < 0) {
+ error_prepend(errp, "failed to read option name length");
+ nbd_send_opt_abort(ioc);
return -1;
}
- opt = be32_to_cpu(opt);
- if (opt != NBD_OPT_LIST) {
- error_setg(errp, "Unexpected option type %" PRIx32 " expected %x",
- opt, NBD_OPT_LIST);
+ namelen = be32_to_cpu(namelen);
+ len -= sizeof(namelen);
+ if (len < namelen) {
+ error_setg(errp, "incorrect option name length");
+ nbd_send_opt_abort(ioc);
return -1;
}
+ if (namelen != strlen(want)) {
+ if (nbd_drop(ioc, len, errp) < 0) {
+ error_prepend(errp, "failed to skip export name with wrong length");
+ nbd_send_opt_abort(ioc);
+ return -1;
+ }
+ return 1;
+ }
- if (read_sync(ioc, &type, sizeof(type)) != sizeof(type)) {
- error_setg(errp, "failed to read list option type");
+ assert(namelen < sizeof(name));
+ if (nbd_read(ioc, name, namelen, errp) < 0) {
+ error_prepend(errp, "failed to read export name");
+ nbd_send_opt_abort(ioc);
return -1;
}
- type = be32_to_cpu(type);
- error = nbd_handle_reply_err(ioc, opt, type, errp);
- if (error <= 0) {
- return error;
+ name[namelen] = '\0';
+ len -= namelen;
+ if (nbd_drop(ioc, len, errp) < 0) {
+ error_prepend(errp, "failed to read export description");
+ nbd_send_opt_abort(ioc);
+ return -1;
+ }
+ if (!strcmp(name, want)) {
+ *match = true;
}
+ return 1;
+}
+
- if (read_sync(ioc, &len, sizeof(len)) != sizeof(len)) {
- error_setg(errp, "failed to read option length");
+/* Returns -1 if NBD_OPT_GO proves the export @wantname cannot be
+ * used, 0 if NBD_OPT_GO is unsupported (fall back to NBD_OPT_LIST and
+ * NBD_OPT_EXPORT_NAME in that case), and > 0 if the export is good to
+ * go (with @info populated). */
+static int nbd_opt_go(QIOChannel *ioc, const char *wantname,
+ NBDExportInfo *info, Error **errp)
+{
+ nbd_opt_reply reply;
+ uint32_t len = strlen(wantname);
+ uint16_t type;
+ int error;
+ char *buf;
+
+ /* The protocol requires that the server send NBD_INFO_EXPORT with
+ * a non-zero flags (at least NBD_FLAG_HAS_FLAGS must be set); so
+ * flags still 0 is a witness of a broken server. */
+ info->flags = 0;
+
+ trace_nbd_opt_go_start(wantname);
+ buf = g_malloc(4 + len + 2 + 2 * info->request_sizes + 1);
+ stl_be_p(buf, len);
+ memcpy(buf + 4, wantname, len);
+ /* At most one request, everything else up to server */
+ stw_be_p(buf + 4 + len, info->request_sizes);
+ if (info->request_sizes) {
+ stw_be_p(buf + 4 + len + 2, NBD_INFO_BLOCK_SIZE);
+ }
+ error = nbd_send_option_request(ioc, NBD_OPT_GO,
+ 4 + len + 2 + 2 * info->request_sizes,
+ buf, errp);
+ g_free(buf);
+ if (error < 0) {
return -1;
}
- len = be32_to_cpu(len);
- if (type == NBD_REP_ACK) {
- if (len != 0) {
- error_setg(errp, "length too long for option end");
+ while (1) {
+ if (nbd_receive_option_reply(ioc, NBD_OPT_GO, &reply, errp) < 0) {
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;
+ error = nbd_handle_reply_err(ioc, &reply, errp);
+ if (error <= 0) {
+ return error;
}
- if (read_sync(ioc, &namelen, sizeof(namelen)) != sizeof(namelen)) {
- error_setg(errp, "failed to read option name length");
- return -1;
+ len = reply.length;
+
+ if (reply.type == NBD_REP_ACK) {
+ /* Server is done sending info and moved into transmission
+ phase, but make sure it sent flags */
+ if (len) {
+ error_setg(errp, "server sent invalid NBD_REP_ACK");
+ return -1;
+ }
+ if (!info->flags) {
+ error_setg(errp, "broken server omitted NBD_INFO_EXPORT");
+ return -1;
+ }
+ trace_nbd_opt_go_success();
+ return 1;
}
- namelen = be32_to_cpu(namelen);
- len -= sizeof(namelen);
- if (len < namelen) {
- error_setg(errp, "incorrect option name length");
+ if (reply.type != NBD_REP_INFO) {
+ error_setg(errp, "unexpected reply type %" PRIx32
+ " (%s), expected %x",
+ reply.type, nbd_rep_lookup(reply.type), NBD_REP_INFO);
+ nbd_send_opt_abort(ioc);
return -1;
}
- if (namelen > NBD_MAX_NAME_SIZE) {
- error_setg(errp, "export name length too long %" PRIu32, namelen);
+ if (len < sizeof(type)) {
+ error_setg(errp, "NBD_REP_INFO length %" PRIu32 " is too short",
+ len);
+ nbd_send_opt_abort(ioc);
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;
+ if (nbd_read(ioc, &type, sizeof(type), errp) < 0) {
+ error_prepend(errp, "failed to read info type");
+ nbd_send_opt_abort(ioc);
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;
+ len -= sizeof(type);
+ be16_to_cpus(&type);
+ switch (type) {
+ case NBD_INFO_EXPORT:
+ if (len != sizeof(info->size) + sizeof(info->flags)) {
+ error_setg(errp, "remaining export info len %" PRIu32
+ " is unexpected size", len);
+ nbd_send_opt_abort(ioc);
+ return -1;
+ }
+ if (nbd_read(ioc, &info->size, sizeof(info->size), errp) < 0) {
+ error_prepend(errp, "failed to read info size");
+ nbd_send_opt_abort(ioc);
+ return -1;
+ }
+ be64_to_cpus(&info->size);
+ if (nbd_read(ioc, &info->flags, sizeof(info->flags), errp) < 0) {
+ error_prepend(errp, "failed to read info flags");
+ nbd_send_opt_abort(ioc);
+ return -1;
+ }
+ be16_to_cpus(&info->flags);
+ trace_nbd_receive_negotiate_size_flags(info->size, info->flags);
+ break;
+
+ case NBD_INFO_BLOCK_SIZE:
+ if (len != sizeof(info->min_block) * 3) {
+ error_setg(errp, "remaining export info len %" PRIu32
+ " is unexpected size", len);
+ nbd_send_opt_abort(ioc);
+ return -1;
+ }
+ if (nbd_read(ioc, &info->min_block, sizeof(info->min_block),
+ errp) < 0) {
+ error_prepend(errp, "failed to read info minimum block size");
+ nbd_send_opt_abort(ioc);
+ return -1;
+ }
+ be32_to_cpus(&info->min_block);
+ if (!is_power_of_2(info->min_block)) {
+ error_setg(errp, "server minimum block size %" PRId32
+ "is not a power of two", info->min_block);
+ nbd_send_opt_abort(ioc);
+ return -1;
+ }
+ if (nbd_read(ioc, &info->opt_block, sizeof(info->opt_block),
+ errp) < 0) {
+ error_prepend(errp, "failed to read info preferred block size");
+ nbd_send_opt_abort(ioc);
+ return -1;
+ }
+ be32_to_cpus(&info->opt_block);
+ if (!is_power_of_2(info->opt_block) ||
+ info->opt_block < info->min_block) {
+ error_setg(errp, "server preferred block size %" PRId32
+ "is not valid", info->opt_block);
+ nbd_send_opt_abort(ioc);
+ return -1;
+ }
+ if (nbd_read(ioc, &info->max_block, sizeof(info->max_block),
+ errp) < 0) {
+ error_prepend(errp, "failed to read info maximum block size");
+ nbd_send_opt_abort(ioc);
+ return -1;
+ }
+ be32_to_cpus(&info->max_block);
+ trace_nbd_opt_go_info_block_size(info->min_block, info->opt_block,
+ info->max_block);
+ break;
+
+ default:
+ trace_nbd_opt_go_info_unknown(type, nbd_info_lookup(type));
+ if (nbd_drop(ioc, len, errp) < 0) {
+ error_prepend(errp, "Failed to read info payload");
+ nbd_send_opt_abort(ioc);
return -1;
}
- buf[len] = '\0';
- TRACE("Ignoring export description: %s", buf);
- g_free(buf);
+ break;
}
- } else {
- error_setg(errp, "Unexpected reply type %" PRIx32 " expected %x",
- type, NBD_REP_SERVER);
- return -1;
}
- return 1;
}
-
+/* Return -1 on failure, 0 if wantname is an available export. */
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");
+ trace_nbd_receive_query_exports_start(wantname);
+ if (nbd_send_option_request(ioc, NBD_OPT_LIST, 0, NULL, errp) < 0) {
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);
+ int ret = nbd_receive_list(ioc, wantname, &foundExport, errp);
if (ret < 0) {
- g_free(name);
- name = NULL;
+ /* Server gave unexpected reply */
return -1;
+ } else if (ret == 0) {
+ /* Done iterating. */
+ if (!foundExport) {
+ error_setg(errp, "No export with name '%s' available",
+ wantname);
+ nbd_send_opt_abort(ioc);
+ return -1;
+ }
+ trace_nbd_receive_query_exports_success(wantname);
+ return 0;
}
- 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;
+ 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");
+ trace_nbd_receive_starttls_request();
+ if (nbd_send_option_request(ioc, NBD_OPT_STARTTLS, 0, NULL, errp) < 0) {
return NULL;
}
- if (write_sync(ioc, &opt, sizeof(opt)) != sizeof(opt)) {
- error_setg(errp, "Failed to send option number");
+ trace_nbd_receive_starttls_reply();
+ if (nbd_receive_option_reply(ioc, NBD_OPT_STARTTLS, &reply, errp) < 0) {
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 %" PRIx32 " 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) {
+ if (reply.type != NBD_REP_ACK) {
error_setg(errp, "Server rejected request to start TLS %" PRIx32,
- type);
+ reply.type);
+ nbd_send_opt_abort(ioc);
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) {
+ if (reply.length != 0) {
error_setg(errp, "Start TLS response was not zero %" PRIu32,
- length);
+ reply.length);
+ nbd_send_opt_abort(ioc);
return NULL;
}
- TRACE("TLS request approved, setting up TLS");
+ trace_nbd_receive_starttls_new_client();
tioc = qio_channel_tls_new_client(ioc, tlscreds, hostname, errp);
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 handshake");
+ trace_nbd_receive_starttls_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,
QCryptoTLSCreds *tlscreds, const char *hostname,
- QIOChannel **outioc,
- off_t *size, Error **errp)
+ QIOChannel **outioc, NBDExportInfo *info,
+ Error **errp)
{
char buf[256];
- uint64_t magic, s;
+ uint64_t magic;
int rc;
+ bool zeroes = true;
- TRACE("Receiving negotiation tlscreds=%p hostname=%s.",
- tlscreds, hostname ? hostname : "<null>");
+ trace_nbd_receive_negotiate(tlscreds, hostname ? hostname : "<null>");
rc = -EINVAL;
goto fail;
}
- if (read_sync(ioc, buf, 8) != 8) {
- error_setg(errp, "Failed to read data");
+ if (nbd_read(ioc, buf, 8, errp) < 0) {
+ error_prepend(errp, "Failed to read data");
goto fail;
}
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] : '.');
+ magic = ldq_be_p(buf);
+ trace_nbd_receive_negotiate_magic(magic);
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");
+ if (nbd_read(ioc, &magic, sizeof(magic), errp) < 0) {
+ error_prepend(errp, "Failed to read magic");
goto fail;
}
magic = be64_to_cpu(magic);
- TRACE("Magic is 0x%" PRIx64, magic);
+ trace_nbd_receive_negotiate_magic(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");
+ if (nbd_read(ioc, &globalflags, sizeof(globalflags), errp) < 0) {
+ error_prepend(errp, "Failed to read server flags");
goto fail;
}
globalflags = be16_to_cpu(globalflags);
- *flags = globalflags << 16;
- TRACE("Global flags are %" PRIx32, globalflags);
+ trace_nbd_receive_negotiate_server_flags(globalflags);
if (globalflags & NBD_FLAG_FIXED_NEWSTYLE) {
fixedNewStyle = true;
- TRACE("Server supports fixed new style");
clientflags |= NBD_FLAG_C_FIXED_NEWSTYLE;
}
+ if (globalflags & NBD_FLAG_NO_ZEROES) {
+ zeroes = false;
+ clientflags |= NBD_FLAG_C_NO_ZEROES;
+ }
/* 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");
+ if (nbd_write(ioc, &clientflags, sizeof(clientflags), errp) < 0) {
+ error_prepend(errp, "Failed to send clientflags field");
goto fail;
}
if (tlscreds) {
}
}
if (!name) {
- TRACE("Using default NBD export name \"\"");
+ trace_nbd_receive_negotiate_default_name();
name = "";
}
if (fixedNewStyle) {
+ int result;
+
+ /* Try NBD_OPT_GO first - if it works, we are done (it
+ * also gives us a good message if the server requires
+ * TLS). If it is not available, fall back to
+ * NBD_OPT_LIST for nicer error messages about a missing
+ * export, then use NBD_OPT_EXPORT_NAME. */
+ result = nbd_opt_go(ioc, name, info, errp);
+ if (result < 0) {
+ goto fail;
+ }
+ if (result > 0) {
+ return 0;
+ }
/* 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
+ * query gives us better error reporting if the
+ * export name is not available.
*/
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");
+ /* write the export name request */
+ if (nbd_send_option_request(ioc, NBD_OPT_EXPORT_NAME, -1, name,
+ errp) < 0) {
goto fail;
}
- if (read_sync(ioc, &s, sizeof(s)) != sizeof(s)) {
- error_setg(errp, "Failed to read export length");
+ /* Read the response */
+ if (nbd_read(ioc, &info->size, sizeof(info->size), errp) < 0) {
+ error_prepend(errp, "Failed to read export length");
goto fail;
}
- *size = be64_to_cpu(s);
- TRACE("Size is %" PRIu64, *size);
+ be64_to_cpus(&info->size);
- if (read_sync(ioc, &exportflags, sizeof(exportflags)) !=
- sizeof(exportflags)) {
- error_setg(errp, "Failed to read export flags");
+ if (nbd_read(ioc, &info->flags, sizeof(info->flags), errp) < 0) {
+ error_prepend(errp, "Failed to read export flags");
goto fail;
}
- exportflags = be16_to_cpu(exportflags);
- *flags |= exportflags;
- TRACE("Export flags are %" PRIx16, exportflags);
+ be16_to_cpus(&info->flags);
} else if (magic == NBD_CLIENT_MAGIC) {
+ uint32_t oldflags;
+
if (name) {
error_setg(errp, "Server does not support export names");
goto fail;
goto fail;
}
- if (read_sync(ioc, &s, sizeof(s)) != sizeof(s)) {
- error_setg(errp, "Failed to read export length");
+ if (nbd_read(ioc, &info->size, sizeof(info->size), errp) < 0) {
+ error_prepend(errp, "Failed to read export length");
goto fail;
}
- *size = be64_to_cpu(s);
- TRACE("Size is %" PRIu64, *size);
+ be64_to_cpus(&info->size);
- if (read_sync(ioc, flags, sizeof(*flags)) != sizeof(*flags)) {
- error_setg(errp, "Failed to read export flags");
+ if (nbd_read(ioc, &oldflags, sizeof(oldflags), errp) < 0) {
+ error_prepend(errp, "Failed to read export flags");
+ goto fail;
+ }
+ be32_to_cpus(&oldflags);
+ if (oldflags & ~0xffff) {
+ error_setg(errp, "Unexpected export flags %0x" PRIx32, oldflags);
goto fail;
}
- *flags = be32_to_cpu(*flags);
+ info->flags = oldflags;
} else {
error_setg(errp, "Bad magic received");
goto fail;
}
- if (read_sync(ioc, &buf, 124) != 124) {
- error_setg(errp, "Failed to read reserved block");
+ 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;
}
rc = 0;
}
#ifdef __linux__
-int nbd_init(int fd, QIOChannelSocket *sioc, uint32_t flags, off_t size)
+int nbd_init(int fd, QIOChannelSocket *sioc, NBDExportInfo *info,
+ Error **errp)
{
- 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);
+ unsigned long sector_size = MAX(BDRV_SECTOR_SIZE, info->min_block);
+ unsigned long sectors = info->size / sector_size;
+
+ /* FIXME: Once the kernel module is patched to honor block sizes,
+ * and to advertise that fact to user space, we should update the
+ * hand-off to the kernel to use any block sizes we learned. */
+ assert(!info->request_sizes);
+ if (info->size / sector_size != sectors) {
+ error_setg(errp, "Export size %" PRIu64 " too large for 32-bit kernel",
+ info->size);
return -E2BIG;
}
- TRACE("Setting NBD socket");
+ trace_nbd_init_set_socket();
if (ioctl(fd, NBD_SET_SOCK, (unsigned long) sioc->fd) < 0) {
int serrno = errno;
- LOG("Failed to set NBD socket");
+ error_setg(errp, "Failed to set NBD socket");
return -serrno;
}
- TRACE("Setting block size to %lu", (unsigned long)BDRV_SECTOR_SIZE);
+ trace_nbd_init_set_block_size(sector_size);
- if (ioctl(fd, NBD_SET_BLKSIZE, (unsigned long)BDRV_SECTOR_SIZE) < 0) {
+ if (ioctl(fd, NBD_SET_BLKSIZE, sector_size) < 0) {
int serrno = errno;
- LOG("Failed setting NBD block size");
+ error_setg(errp, "Failed setting NBD block size");
return -serrno;
}
- 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));
+ trace_nbd_init_set_size(sectors);
+ if (info->size % sector_size) {
+ trace_nbd_init_trailing_bytes(info->size % sector_size);
}
if (ioctl(fd, NBD_SET_SIZE_BLOCKS, sectors) < 0) {
int serrno = errno;
- LOG("Failed setting size (in blocks)");
+ error_setg(errp, "Failed setting size (in blocks)");
return -serrno;
}
- if (ioctl(fd, NBD_SET_FLAGS, (unsigned long) flags) < 0) {
+ if (ioctl(fd, NBD_SET_FLAGS, (unsigned long) info->flags) < 0) {
if (errno == ENOTTY) {
- int read_only = (flags & NBD_FLAG_READ_ONLY) != 0;
- TRACE("Setting readonly attribute");
+ int read_only = (info->flags & NBD_FLAG_READ_ONLY) != 0;
+ trace_nbd_init_set_readonly();
if (ioctl(fd, BLKROSET, (unsigned long) &read_only) < 0) {
int serrno = errno;
- LOG("Failed setting read-only attribute");
+ error_setg(errp, "Failed setting read-only attribute");
return -serrno;
}
} else {
int serrno = errno;
- LOG("Failed setting flags");
+ error_setg(errp, "Failed setting flags");
return -serrno;
}
}
- TRACE("Negotiation ended");
+ trace_nbd_init_finish();
return 0;
}
int ret;
int serrno;
- TRACE("Doing NBD loop");
+ trace_nbd_client_loop();
ret = ioctl(fd, NBD_DO_IT);
if (ret < 0 && errno == EPIPE) {
}
serrno = errno;
- TRACE("NBD loop returned %d: %s", ret, strerror(serrno));
+ trace_nbd_client_loop_ret(ret, strerror(serrno));
- TRACE("Clearing NBD queue");
+ trace_nbd_client_clear_queue();
ioctl(fd, NBD_CLEAR_QUE);
- TRACE("Clearing NBD socket");
+ trace_nbd_client_clear_socket();
ioctl(fd, NBD_CLEAR_SOCK);
errno = serrno;
}
#else
-int nbd_init(int fd, QIOChannelSocket *ioc, uint32_t flags, off_t size)
+int nbd_init(int fd, QIOChannelSocket *ioc, NBDExportInfo *info,
+ Error **errp)
{
+ error_setg(errp, "nbd_init is only supported on Linux");
return -ENOTSUP;
}
}
#endif
-ssize_t nbd_send_request(QIOChannel *ioc, struct nbd_request *request)
+int nbd_send_request(QIOChannel *ioc, NBDRequest *request)
{
uint8_t buf[NBD_REQUEST_SIZE];
- ssize_t ret;
- TRACE("Sending request to server: "
- "{ .from = %" PRIu64", .len = %" PRIu32 ", .handle = %" PRIu64
- ", .type=%" PRIu32 " }",
- request->from, request->len, request->handle, request->type);
+ trace_nbd_send_request(request->from, request->len, request->handle,
+ request->flags, request->type,
+ nbd_cmd_lookup(request->type));
stl_be_p(buf, NBD_REQUEST_MAGIC);
- stl_be_p(buf + 4, request->type);
+ 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 ret;
- }
-
- if (ret != sizeof(buf)) {
- LOG("writing to socket failed");
- return -EINVAL;
- }
- return 0;
+ return nbd_write(ioc, buf, sizeof(buf), NULL);
}
-ssize_t nbd_receive_reply(QIOChannel *ioc, struct nbd_reply *reply)
+/* nbd_receive_reply
+ * Returns 1 on success
+ * 0 on eof, when no data was read (errp is not set)
+ * negative errno on failure (errp is set)
+ */
+int nbd_receive_reply(QIOChannel *ioc, NBDReply *reply, Error **errp)
{
uint8_t buf[NBD_REPLY_SIZE];
uint32_t magic;
- ssize_t ret;
+ int ret;
- ret = read_sync(ioc, buf, sizeof(buf));
- if (ret < 0) {
+ ret = nbd_read_eof(ioc, buf, sizeof(buf), errp);
+ 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)
reply->error = nbd_errno_to_system_errno(reply->error);
- TRACE("Got reply: { magic = 0x%" PRIx32 ", .error = % " PRId32
- ", handle = %" PRIu64" }",
- magic, reply->error, reply->handle);
+ if (reply->error == ESHUTDOWN) {
+ /* This works even on mingw which lacks a native ESHUTDOWN */
+ error_setg(errp, "server shutting down");
+ return -EINVAL;
+ }
+ trace_nbd_receive_reply(magic, reply->error, reply->handle);
if (magic != NBD_REPLY_MAGIC) {
- LOG("invalid magic (got 0x%" PRIx32 ")", magic);
+ error_setg(errp, "invalid magic (got 0x%" PRIx32 ")", magic);
return -EINVAL;
}
- return 0;
+
+ return 1;
}
projects / qemu.git / blobdiff