Merge remote-tracking branch 'remotes/bonzini-gitlab/tags/for-upstream' into staging
[qemu.git] / blockdev-nbd.c
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 */
11
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"
23
24 typedef struct NBDServerData {
25 QIONetListener *listener;
26 QCryptoTLSCreds *tlscreds;
27 char *tlsauthz;
28 uint32_t max_connections;
29 uint32_t connections;
30 } NBDServerData;
31
32 static NBDServerData *nbd_server;
33 static bool is_qemu_nbd;
34
35 static void nbd_update_server_watch(NBDServerData *s);
36
37 void nbd_server_is_qemu_nbd(bool value)
38 {
39 is_qemu_nbd = value;
40 }
41
42 bool nbd_server_is_running(void)
43 {
44 return nbd_server || is_qemu_nbd;
45 }
46
47 static void nbd_blockdev_client_closed(NBDClient *client, bool ignored)
48 {
49 nbd_client_put(client);
50 assert(nbd_server->connections > 0);
51 nbd_server->connections--;
52 nbd_update_server_watch(nbd_server);
53 }
54
55 static void nbd_accept(QIONetListener *listener, QIOChannelSocket *cioc,
56 gpointer opaque)
57 {
58 nbd_server->connections++;
59 nbd_update_server_watch(nbd_server);
60
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);
64 }
65
66 static void nbd_update_server_watch(NBDServerData *s)
67 {
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 }
73 }
74
75 static void nbd_server_free(NBDServerData *server)
76 {
77 if (!server) {
78 return;
79 }
80
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);
87
88 g_free(server);
89 }
90
91 static QCryptoTLSCreds *nbd_get_tls_creds(const char *id, Error **errp)
92 {
93 Object *obj;
94 QCryptoTLSCreds *creds;
95
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 }
110
111 if (!qcrypto_tls_creds_check_endpoint(creds,
112 QCRYPTO_TLS_CREDS_ENDPOINT_SERVER,
113 errp)) {
114 return NULL;
115 }
116 object_ref(obj);
117 return creds;
118 }
119
120
121 void nbd_server_start(SocketAddress *addr, const char *tls_creds,
122 const char *tls_authz, uint32_t max_connections,
123 Error **errp)
124 {
125 if (nbd_server) {
126 error_setg(errp, "NBD server already running");
127 return;
128 }
129
130 nbd_server = g_new0(NBDServerData, 1);
131 nbd_server->max_connections = max_connections;
132 nbd_server->listener = qio_net_listener_new();
133
134 qio_net_listener_set_name(nbd_server->listener,
135 "nbd-listener");
136
137 /*
138 * Because this server is persistent, a backlog of SOMAXCONN is
139 * better than trying to size it to max_connections.
140 */
141 if (qio_net_listener_open_sync(nbd_server->listener, addr, SOMAXCONN,
142 errp) < 0) {
143 goto error;
144 }
145
146 if (tls_creds) {
147 nbd_server->tlscreds = nbd_get_tls_creds(tls_creds, errp);
148 if (!nbd_server->tlscreds) {
149 goto error;
150 }
151
152 /* TODO SOCKET_ADDRESS_TYPE_FD where fd has AF_INET or AF_INET6 */
153 if (addr->type != SOCKET_ADDRESS_TYPE_INET) {
154 error_setg(errp, "TLS is only supported with IPv4/IPv6");
155 goto error;
156 }
157 }
158
159 nbd_server->tlsauthz = g_strdup(tls_authz);
160
161 nbd_update_server_watch(nbd_server);
162
163 return;
164
165 error:
166 nbd_server_free(nbd_server);
167 nbd_server = NULL;
168 }
169
170 void nbd_server_start_options(NbdServerOptions *arg, Error **errp)
171 {
172 nbd_server_start(arg->addr, arg->tls_creds, arg->tls_authz,
173 arg->max_connections, errp);
174 }
175
176 void qmp_nbd_server_start(SocketAddressLegacy *addr,
177 bool has_tls_creds, const char *tls_creds,
178 bool has_tls_authz, const char *tls_authz,
179 bool has_max_connections, uint32_t max_connections,
180 Error **errp)
181 {
182 SocketAddress *addr_flat = socket_address_flatten(addr);
183
184 nbd_server_start(addr_flat, tls_creds, tls_authz, max_connections, errp);
185 qapi_free_SocketAddress(addr_flat);
186 }
187
188 void qmp_nbd_server_add(NbdServerAddOptions *arg, Error **errp)
189 {
190 BlockExport *export;
191 BlockDriverState *bs;
192 BlockBackend *on_eject_blk;
193 BlockExportOptions *export_opts;
194
195 bs = bdrv_lookup_bs(arg->device, arg->device, errp);
196 if (!bs) {
197 return;
198 }
199
200 /*
201 * block-export-add would default to the node-name, but we may have to use
202 * the device name as a default here for compatibility.
203 */
204 if (!arg->has_name) {
205 arg->has_name = true;
206 arg->name = g_strdup(arg->device);
207 }
208
209 export_opts = g_new(BlockExportOptions, 1);
210 *export_opts = (BlockExportOptions) {
211 .type = BLOCK_EXPORT_TYPE_NBD,
212 .id = g_strdup(arg->name),
213 .node_name = g_strdup(bdrv_get_node_name(bs)),
214 .has_writable = arg->has_writable,
215 .writable = arg->writable,
216 };
217 QAPI_CLONE_MEMBERS(BlockExportOptionsNbdBase, &export_opts->u.nbd,
218 qapi_NbdServerAddOptions_base(arg));
219 if (arg->has_bitmap) {
220 export_opts->u.nbd.has_bitmaps = true;
221 QAPI_LIST_PREPEND(export_opts->u.nbd.bitmaps, g_strdup(arg->bitmap));
222 }
223
224 /*
225 * nbd-server-add doesn't complain when a read-only device should be
226 * exported as writable, but simply downgrades it. This is an error with
227 * block-export-add.
228 */
229 if (bdrv_is_read_only(bs)) {
230 export_opts->has_writable = true;
231 export_opts->writable = false;
232 }
233
234 export = blk_exp_add(export_opts, errp);
235 if (!export) {
236 goto fail;
237 }
238
239 /*
240 * nbd-server-add removes the export when the named BlockBackend used for
241 * @device goes away.
242 */
243 on_eject_blk = blk_by_name(arg->device);
244 if (on_eject_blk) {
245 nbd_export_set_on_eject_blk(export, on_eject_blk);
246 }
247
248 fail:
249 qapi_free_BlockExportOptions(export_opts);
250 }
251
252 void qmp_nbd_server_remove(const char *name,
253 bool has_mode, BlockExportRemoveMode mode,
254 Error **errp)
255 {
256 BlockExport *exp;
257
258 exp = blk_exp_find(name);
259 if (exp && exp->drv->type != BLOCK_EXPORT_TYPE_NBD) {
260 error_setg(errp, "Block export '%s' is not an NBD export", name);
261 return;
262 }
263
264 qmp_block_export_del(name, has_mode, mode, errp);
265 }
266
267 void qmp_nbd_server_stop(Error **errp)
268 {
269 if (!nbd_server) {
270 error_setg(errp, "NBD server not running");
271 return;
272 }
273
274 blk_exp_close_all_type(BLOCK_EXPORT_TYPE_NBD);
275
276 nbd_server_free(nbd_server);
277 nbd_server = NULL;
278 }