spapr: spapr_drc_attach() cannot fail
[qemu/ar7.git] / blockdev-nbd.c
blobd8443d235b7338949a4e6e10dec5a8cc88fa9f32
1 /*
2  * Serving QEMU block devices via NBD
3  *
4  * Copyright (c) 2012 Red Hat, Inc.
5  *
6  * Author: Paolo Bonzini <pbonzini@redhat.com>
7  *
8  * This work is licensed under the terms of the GNU GPL, version 2 or
9  * later.  See the COPYING file in the top-level directory.
10  */
12 #include "qemu/osdep.h"
13 #include "sysemu/blockdev.h"
14 #include "sysemu/block-backend.h"
15 #include "hw/block/block.h"
16 #include "qapi/error.h"
17 #include "qapi/clone-visitor.h"
18 #include "qapi/qapi-visit-block-export.h"
19 #include "qapi/qapi-commands-block-export.h"
20 #include "block/nbd.h"
21 #include "io/channel-socket.h"
22 #include "io/net-listener.h"
24 typedef struct NBDServerData {
25     QIONetListener *listener;
26     QCryptoTLSCreds *tlscreds;
27     char *tlsauthz;
28     uint32_t max_connections;
29     uint32_t connections;
30 } NBDServerData;
32 static NBDServerData *nbd_server;
33 static bool is_qemu_nbd;
35 static void nbd_update_server_watch(NBDServerData *s);
37 void nbd_server_is_qemu_nbd(bool value)
39     is_qemu_nbd = value;
42 bool nbd_server_is_running(void)
44     return nbd_server || is_qemu_nbd;
47 static void nbd_blockdev_client_closed(NBDClient *client, bool ignored)
49     nbd_client_put(client);
50     assert(nbd_server->connections > 0);
51     nbd_server->connections--;
52     nbd_update_server_watch(nbd_server);
55 static void nbd_accept(QIONetListener *listener, QIOChannelSocket *cioc,
56                        gpointer opaque)
58     nbd_server->connections++;
59     nbd_update_server_watch(nbd_server);
61     qio_channel_set_name(QIO_CHANNEL(cioc), "nbd-server");
62     nbd_client_new(cioc, nbd_server->tlscreds, nbd_server->tlsauthz,
63                    nbd_blockdev_client_closed);
66 static void nbd_update_server_watch(NBDServerData *s)
68     if (!s->max_connections || s->connections < s->max_connections) {
69         qio_net_listener_set_client_func(s->listener, nbd_accept, NULL, NULL);
70     } else {
71         qio_net_listener_set_client_func(s->listener, NULL, NULL, NULL);
72     }
75 static void nbd_server_free(NBDServerData *server)
77     if (!server) {
78         return;
79     }
81     qio_net_listener_disconnect(server->listener);
82     object_unref(OBJECT(server->listener));
83     if (server->tlscreds) {
84         object_unref(OBJECT(server->tlscreds));
85     }
86     g_free(server->tlsauthz);
88     g_free(server);
91 static QCryptoTLSCreds *nbd_get_tls_creds(const char *id, Error **errp)
93     Object *obj;
94     QCryptoTLSCreds *creds;
96     obj = object_resolve_path_component(
97         object_get_objects_root(), id);
98     if (!obj) {
99         error_setg(errp, "No TLS credentials with id '%s'",
100                    id);
101         return NULL;
102     }
103     creds = (QCryptoTLSCreds *)
104         object_dynamic_cast(obj, TYPE_QCRYPTO_TLS_CREDS);
105     if (!creds) {
106         error_setg(errp, "Object with id '%s' is not TLS credentials",
107                    id);
108         return NULL;
109     }
111     if (creds->endpoint != QCRYPTO_TLS_CREDS_ENDPOINT_SERVER) {
112         error_setg(errp,
113                    "Expecting TLS credentials with a server endpoint");
114         return NULL;
115     }
116     object_ref(obj);
117     return creds;
121 void nbd_server_start(SocketAddress *addr, const char *tls_creds,
122                       const char *tls_authz, uint32_t max_connections,
123                       Error **errp)
125     if (nbd_server) {
126         error_setg(errp, "NBD server already running");
127         return;
128     }
130     nbd_server = g_new0(NBDServerData, 1);
131     nbd_server->max_connections = max_connections;
132     nbd_server->listener = qio_net_listener_new();
134     qio_net_listener_set_name(nbd_server->listener,
135                               "nbd-listener");
137     if (qio_net_listener_open_sync(nbd_server->listener, addr, 1, errp) < 0) {
138         goto error;
139     }
141     if (tls_creds) {
142         nbd_server->tlscreds = nbd_get_tls_creds(tls_creds, errp);
143         if (!nbd_server->tlscreds) {
144             goto error;
145         }
147         /* TODO SOCKET_ADDRESS_TYPE_FD where fd has AF_INET or AF_INET6 */
148         if (addr->type != SOCKET_ADDRESS_TYPE_INET) {
149             error_setg(errp, "TLS is only supported with IPv4/IPv6");
150             goto error;
151         }
152     }
154     nbd_server->tlsauthz = g_strdup(tls_authz);
156     nbd_update_server_watch(nbd_server);
158     return;
160  error:
161     nbd_server_free(nbd_server);
162     nbd_server = NULL;
165 void nbd_server_start_options(NbdServerOptions *arg, Error **errp)
167     nbd_server_start(arg->addr, arg->tls_creds, arg->tls_authz,
168                      arg->max_connections, errp);
171 void qmp_nbd_server_start(SocketAddressLegacy *addr,
172                           bool has_tls_creds, const char *tls_creds,
173                           bool has_tls_authz, const char *tls_authz,
174                           bool has_max_connections, uint32_t max_connections,
175                           Error **errp)
177     SocketAddress *addr_flat = socket_address_flatten(addr);
179     nbd_server_start(addr_flat, tls_creds, tls_authz, max_connections, errp);
180     qapi_free_SocketAddress(addr_flat);
183 void qmp_nbd_server_add(NbdServerAddOptions *arg, Error **errp)
185     BlockExport *export;
186     BlockDriverState *bs;
187     BlockBackend *on_eject_blk;
188     BlockExportOptions *export_opts;
190     bs = bdrv_lookup_bs(arg->device, arg->device, errp);
191     if (!bs) {
192         return;
193     }
195     /*
196      * block-export-add would default to the node-name, but we may have to use
197      * the device name as a default here for compatibility.
198      */
199     if (!arg->has_name) {
200         arg->has_name = true;
201         arg->name = g_strdup(arg->device);
202     }
204     export_opts = g_new(BlockExportOptions, 1);
205     *export_opts = (BlockExportOptions) {
206         .type                   = BLOCK_EXPORT_TYPE_NBD,
207         .id                     = g_strdup(arg->name),
208         .node_name              = g_strdup(bdrv_get_node_name(bs)),
209         .has_writable           = arg->has_writable,
210         .writable               = arg->writable,
211     };
212     QAPI_CLONE_MEMBERS(BlockExportOptionsNbdBase, &export_opts->u.nbd,
213                        qapi_NbdServerAddOptions_base(arg));
214     if (arg->has_bitmap) {
215         export_opts->u.nbd.has_bitmaps = true;
216         QAPI_LIST_PREPEND(export_opts->u.nbd.bitmaps, g_strdup(arg->bitmap));
217     }
219     /*
220      * nbd-server-add doesn't complain when a read-only device should be
221      * exported as writable, but simply downgrades it. This is an error with
222      * block-export-add.
223      */
224     if (bdrv_is_read_only(bs)) {
225         export_opts->has_writable = true;
226         export_opts->writable = false;
227     }
229     export = blk_exp_add(export_opts, errp);
230     if (!export) {
231         goto fail;
232     }
234     /*
235      * nbd-server-add removes the export when the named BlockBackend used for
236      * @device goes away.
237      */
238     on_eject_blk = blk_by_name(arg->device);
239     if (on_eject_blk) {
240         nbd_export_set_on_eject_blk(export, on_eject_blk);
241     }
243 fail:
244     qapi_free_BlockExportOptions(export_opts);
247 void qmp_nbd_server_remove(const char *name,
248                            bool has_mode, BlockExportRemoveMode mode,
249                            Error **errp)
251     BlockExport *exp;
253     exp = blk_exp_find(name);
254     if (exp && exp->drv->type != BLOCK_EXPORT_TYPE_NBD) {
255         error_setg(errp, "Block export '%s' is not an NBD export", name);
256         return;
257     }
259     qmp_block_export_del(name, has_mode, mode, errp);
262 void qmp_nbd_server_stop(Error **errp)
264     if (!nbd_server) {
265         error_setg(errp, "NBD server not running");
266         return;
267     }
269     blk_exp_close_all_type(BLOCK_EXPORT_TYPE_NBD);
271     nbd_server_free(nbd_server);
272     nbd_server = NULL;