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- /*
- * Serving QEMU block devices via NBD
- *
- * Copyright (c) 2012 Red Hat, Inc.
- *
- * Author: Paolo Bonzini <pbonzini@redhat.com>
- *
- * This work is licensed under the terms of the GNU GPL, version 2 or
- * later. See the COPYING file in the top-level directory.
- */
- #include "qemu/osdep.h"
- #include "sysemu/blockdev.h"
- #include "sysemu/block-backend.h"
- #include "hw/block/block.h"
- #include "qapi/error.h"
- #include "qapi/qapi-commands-block.h"
- #include "block/nbd.h"
- #include "io/channel-socket.h"
- #include "io/net-listener.h"
- typedef struct NBDServerData {
- QIONetListener *listener;
- QCryptoTLSCreds *tlscreds;
- char *tlsauthz;
- } NBDServerData;
- static NBDServerData *nbd_server;
- static void nbd_blockdev_client_closed(NBDClient *client, bool ignored)
- {
- nbd_client_put(client);
- }
- static void nbd_accept(QIONetListener *listener, QIOChannelSocket *cioc,
- gpointer opaque)
- {
- qio_channel_set_name(QIO_CHANNEL(cioc), "nbd-server");
- nbd_client_new(cioc, nbd_server->tlscreds, nbd_server->tlsauthz,
- nbd_blockdev_client_closed);
- }
- static void nbd_server_free(NBDServerData *server)
- {
- if (!server) {
- return;
- }
- qio_net_listener_disconnect(server->listener);
- object_unref(OBJECT(server->listener));
- if (server->tlscreds) {
- object_unref(OBJECT(server->tlscreds));
- }
- g_free(server->tlsauthz);
- g_free(server);
- }
- static QCryptoTLSCreds *nbd_get_tls_creds(const char *id, Error **errp)
- {
- Object *obj;
- QCryptoTLSCreds *creds;
- obj = object_resolve_path_component(
- object_get_objects_root(), id);
- if (!obj) {
- error_setg(errp, "No TLS credentials with id '%s'",
- id);
- return NULL;
- }
- creds = (QCryptoTLSCreds *)
- object_dynamic_cast(obj, TYPE_QCRYPTO_TLS_CREDS);
- if (!creds) {
- error_setg(errp, "Object with id '%s' is not TLS credentials",
- id);
- return NULL;
- }
- if (creds->endpoint != QCRYPTO_TLS_CREDS_ENDPOINT_SERVER) {
- error_setg(errp,
- "Expecting TLS credentials with a server endpoint");
- return NULL;
- }
- object_ref(obj);
- return creds;
- }
- void nbd_server_start(SocketAddress *addr, const char *tls_creds,
- const char *tls_authz, Error **errp)
- {
- if (nbd_server) {
- error_setg(errp, "NBD server already running");
- return;
- }
- nbd_server = g_new0(NBDServerData, 1);
- nbd_server->listener = qio_net_listener_new();
- qio_net_listener_set_name(nbd_server->listener,
- "nbd-listener");
- if (qio_net_listener_open_sync(nbd_server->listener, addr, 1, errp) < 0) {
- goto error;
- }
- if (tls_creds) {
- nbd_server->tlscreds = nbd_get_tls_creds(tls_creds, errp);
- if (!nbd_server->tlscreds) {
- goto error;
- }
- /* TODO SOCKET_ADDRESS_TYPE_FD where fd has AF_INET or AF_INET6 */
- if (addr->type != SOCKET_ADDRESS_TYPE_INET) {
- error_setg(errp, "TLS is only supported with IPv4/IPv6");
- goto error;
- }
- }
- nbd_server->tlsauthz = g_strdup(tls_authz);
- qio_net_listener_set_client_func(nbd_server->listener,
- nbd_accept,
- NULL,
- NULL);
- return;
- error:
- nbd_server_free(nbd_server);
- nbd_server = NULL;
- }
- void qmp_nbd_server_start(SocketAddressLegacy *addr,
- bool has_tls_creds, const char *tls_creds,
- bool has_tls_authz, const char *tls_authz,
- Error **errp)
- {
- SocketAddress *addr_flat = socket_address_flatten(addr);
- nbd_server_start(addr_flat, tls_creds, tls_authz, errp);
- qapi_free_SocketAddress(addr_flat);
- }
- void qmp_nbd_server_add(const char *device, bool has_name, const char *name,
- bool has_writable, bool writable,
- bool has_bitmap, const char *bitmap, Error **errp)
- {
- BlockDriverState *bs = NULL;
- BlockBackend *on_eject_blk;
- NBDExport *exp;
- int64_t len;
- AioContext *aio_context;
- if (!nbd_server) {
- error_setg(errp, "NBD server not running");
- return;
- }
- if (!has_name) {
- name = device;
- }
- if (strlen(name) > NBD_MAX_STRING_SIZE) {
- error_setg(errp, "export name '%s' too long", name);
- return;
- }
- if (nbd_export_find(name)) {
- error_setg(errp, "NBD server already has export named '%s'", name);
- return;
- }
- on_eject_blk = blk_by_name(device);
- bs = bdrv_lookup_bs(device, device, errp);
- if (!bs) {
- return;
- }
- aio_context = bdrv_get_aio_context(bs);
- aio_context_acquire(aio_context);
- len = bdrv_getlength(bs);
- if (len < 0) {
- error_setg_errno(errp, -len,
- "Failed to determine the NBD export's length");
- goto out;
- }
- if (!has_writable) {
- writable = false;
- }
- if (bdrv_is_read_only(bs)) {
- writable = false;
- }
- exp = nbd_export_new(bs, 0, len, name, NULL, bitmap, !writable, !writable,
- NULL, false, on_eject_blk, errp);
- if (!exp) {
- goto out;
- }
- /* The list of named exports has a strong reference to this export now and
- * our only way of accessing it is through nbd_export_find(), so we can drop
- * the strong reference that is @exp. */
- nbd_export_put(exp);
- out:
- aio_context_release(aio_context);
- }
- void qmp_nbd_server_remove(const char *name,
- bool has_mode, NbdServerRemoveMode mode,
- Error **errp)
- {
- NBDExport *exp;
- AioContext *aio_context;
- if (!nbd_server) {
- error_setg(errp, "NBD server not running");
- return;
- }
- exp = nbd_export_find(name);
- if (exp == NULL) {
- error_setg(errp, "Export '%s' is not found", name);
- return;
- }
- if (!has_mode) {
- mode = NBD_SERVER_REMOVE_MODE_SAFE;
- }
- aio_context = nbd_export_aio_context(exp);
- aio_context_acquire(aio_context);
- nbd_export_remove(exp, mode, errp);
- aio_context_release(aio_context);
- }
- void qmp_nbd_server_stop(Error **errp)
- {
- if (!nbd_server) {
- error_setg(errp, "NBD server not running");
- return;
- }
- nbd_export_close_all();
- nbd_server_free(nbd_server);
- nbd_server = NULL;
- }
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