arm tcg cpus: Fix Lesser GPL version number
[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 (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;
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 if (qio_net_listener_open_sync(nbd_server->listener, addr, 1, errp) < 0) {
138 goto error;
139 }
140
141 if (tls_creds) {
142 nbd_server->tlscreds = nbd_get_tls_creds(tls_creds, errp);
143 if (!nbd_server->tlscreds) {
144 goto error;
145 }
146
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 }
153
154 nbd_server->tlsauthz = g_strdup(tls_authz);
155
156 nbd_update_server_watch(nbd_server);
157
158 return;
159
160 error:
161 nbd_server_free(nbd_server);
162 nbd_server = NULL;
163 }
164
165 void nbd_server_start_options(NbdServerOptions *arg, Error **errp)
166 {
167 nbd_server_start(arg->addr, arg->tls_creds, arg->tls_authz,
168 arg->max_connections, errp);
169 }
170
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)
176 {
177 SocketAddress *addr_flat = socket_address_flatten(addr);
178
179 nbd_server_start(addr_flat, tls_creds, tls_authz, max_connections, errp);
180 qapi_free_SocketAddress(addr_flat);
181 }
182
183 void qmp_nbd_server_add(NbdServerAddOptions *arg, Error **errp)
184 {
185 BlockExport *export;
186 BlockDriverState *bs;
187 BlockBackend *on_eject_blk;
188 BlockExportOptions *export_opts;
189
190 bs = bdrv_lookup_bs(arg->device, arg->device, errp);
191 if (!bs) {
192 return;
193 }
194
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 }
203
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 }
218
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 }
228
229 export = blk_exp_add(export_opts, errp);
230 if (!export) {
231 goto fail;
232 }
233
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 }
242
243 fail:
244 qapi_free_BlockExportOptions(export_opts);
245 }
246
247 void qmp_nbd_server_remove(const char *name,
248 bool has_mode, BlockExportRemoveMode mode,
249 Error **errp)
250 {
251 BlockExport *exp;
252
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 }
258
259 qmp_block_export_del(name, has_mode, mode, errp);
260 }
261
262 void qmp_nbd_server_stop(Error **errp)
263 {
264 if (!nbd_server) {
265 error_setg(errp, "NBD server not running");
266 return;
267 }
268
269 blk_exp_close_all_type(BLOCK_EXPORT_TYPE_NBD);
270
271 nbd_server_free(nbd_server);
272 nbd_server = NULL;
273 }