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Paolo Bonzini6dd844d2012-08-22 16:43:07 +02001/*
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
Peter Maydelld38ea872016-01-29 17:50:05 +000012#include "qemu/osdep.h"
Paolo Bonzini9c17d612012-12-17 18:20:04 +010013#include "sysemu/blockdev.h"
Max Reitze1401772014-11-18 12:21:17 +010014#include "sysemu/block-backend.h"
Paolo Bonzini0d09e412013-02-05 17:06:20 +010015#include "hw/block/block.h"
Markus Armbrustere688df62018-02-01 12:18:31 +010016#include "qapi/error.h"
Eric Blake8675cbd2020-10-27 00:05:48 -050017#include "qapi/clone-visitor.h"
18#include "qapi/qapi-visit-block-export.h"
Kevin Wolf5daa6bf2020-09-24 17:26:48 +020019#include "qapi/qapi-commands-block-export.h"
Paolo Bonzini737e1502012-12-17 18:19:44 +010020#include "block/nbd.h"
Daniel P. Berrangeae398272016-02-10 18:41:03 +000021#include "io/channel-socket.h"
Daniel P. Berrange862172f2017-12-18 10:16:42 +000022#include "io/net-listener.h"
Paolo Bonzini6dd844d2012-08-22 16:43:07 +020023
Daniel P. Berrangeddffee32016-02-10 18:41:14 +000024typedef struct NBDServerData {
Daniel P. Berrange862172f2017-12-18 10:16:42 +000025 QIONetListener *listener;
Daniel P. Berrangeddffee32016-02-10 18:41:14 +000026 QCryptoTLSCreds *tlscreds;
Daniel P. Berrange00019452019-02-27 16:20:34 +000027 char *tlsauthz;
Kevin Wolf1c8222b2020-09-24 17:26:54 +020028 uint32_t max_connections;
29 uint32_t connections;
Daniel P. Berrangeddffee32016-02-10 18:41:14 +000030} NBDServerData;
31
32static NBDServerData *nbd_server;
Eric Blakea5fced42022-05-11 19:49:23 -050033static int qemu_nbd_connections = -1; /* Non-negative if this is qemu-nbd */
Daniel P. Berrangeddffee32016-02-10 18:41:14 +000034
Kevin Wolf1c8222b2020-09-24 17:26:54 +020035static void nbd_update_server_watch(NBDServerData *s);
36
Eric Blakea5fced42022-05-11 19:49:23 -050037void nbd_server_is_qemu_nbd(int max_connections)
Kevin Wolf00917172020-09-24 17:26:57 +020038{
Eric Blakea5fced42022-05-11 19:49:23 -050039 qemu_nbd_connections = max_connections;
Kevin Wolf00917172020-09-24 17:26:57 +020040}
41
Kevin Wolf5b1cb492020-09-24 17:27:12 +020042bool nbd_server_is_running(void)
43{
Eric Blakea5fced42022-05-11 19:49:23 -050044 return nbd_server || qemu_nbd_connections >= 0;
Kevin Wolf5b1cb492020-09-24 17:27:12 +020045}
46
Eric Blake58a6fdc2022-05-11 19:49:24 -050047int nbd_server_max_connections(void)
48{
49 return nbd_server ? nbd_server->max_connections : qemu_nbd_connections;
50}
51
Eric Blake0c9390d2017-06-08 17:26:17 -050052static void nbd_blockdev_client_closed(NBDClient *client, bool ignored)
53{
54 nbd_client_put(client);
Kevin Wolf1c8222b2020-09-24 17:26:54 +020055 assert(nbd_server->connections > 0);
56 nbd_server->connections--;
57 nbd_update_server_watch(nbd_server);
Eric Blake0c9390d2017-06-08 17:26:17 -050058}
Paolo Bonzini6dd844d2012-08-22 16:43:07 +020059
Daniel P. Berrange862172f2017-12-18 10:16:42 +000060static void nbd_accept(QIONetListener *listener, QIOChannelSocket *cioc,
61 gpointer opaque)
Paolo Bonzini6dd844d2012-08-22 16:43:07 +020062{
Kevin Wolf1c8222b2020-09-24 17:26:54 +020063 nbd_server->connections++;
64 nbd_update_server_watch(nbd_server);
65
Daniel P. Berrange0d73f722016-09-30 11:57:14 +010066 qio_channel_set_name(QIO_CHANNEL(cioc), "nbd-server");
Daniel P. Berrange00019452019-02-27 16:20:34 +000067 nbd_client_new(cioc, nbd_server->tlscreds, nbd_server->tlsauthz,
Eric Blake0c9390d2017-06-08 17:26:17 -050068 nbd_blockdev_client_closed);
Paolo Bonzini6dd844d2012-08-22 16:43:07 +020069}
70
Kevin Wolf1c8222b2020-09-24 17:26:54 +020071static void nbd_update_server_watch(NBDServerData *s)
72{
73 if (!s->max_connections || s->connections < s->max_connections) {
74 qio_net_listener_set_client_func(s->listener, nbd_accept, NULL, NULL);
75 } else {
76 qio_net_listener_set_client_func(s->listener, NULL, NULL, NULL);
77 }
78}
Daniel P. Berrangeddffee32016-02-10 18:41:14 +000079
80static void nbd_server_free(NBDServerData *server)
Paolo Bonzini6dd844d2012-08-22 16:43:07 +020081{
Daniel P. Berrangeddffee32016-02-10 18:41:14 +000082 if (!server) {
83 return;
84 }
85
Daniel P. Berrange862172f2017-12-18 10:16:42 +000086 qio_net_listener_disconnect(server->listener);
87 object_unref(OBJECT(server->listener));
Daniel P. Berrangeddffee32016-02-10 18:41:14 +000088 if (server->tlscreds) {
89 object_unref(OBJECT(server->tlscreds));
90 }
Daniel P. Berrange00019452019-02-27 16:20:34 +000091 g_free(server->tlsauthz);
Daniel P. Berrangeddffee32016-02-10 18:41:14 +000092
93 g_free(server);
94}
95
96static QCryptoTLSCreds *nbd_get_tls_creds(const char *id, Error **errp)
97{
98 Object *obj;
99 QCryptoTLSCreds *creds;
100
101 obj = object_resolve_path_component(
102 object_get_objects_root(), id);
103 if (!obj) {
104 error_setg(errp, "No TLS credentials with id '%s'",
105 id);
106 return NULL;
107 }
108 creds = (QCryptoTLSCreds *)
109 object_dynamic_cast(obj, TYPE_QCRYPTO_TLS_CREDS);
110 if (!creds) {
111 error_setg(errp, "Object with id '%s' is not TLS credentials",
112 id);
113 return NULL;
114 }
115
Philippe Mathieu-Daudé7b3b6162021-06-28 18:09:09 +0200116 if (!qcrypto_tls_creds_check_endpoint(creds,
117 QCRYPTO_TLS_CREDS_ENDPOINT_SERVER,
118 errp)) {
Daniel P. Berrangeddffee32016-02-10 18:41:14 +0000119 return NULL;
120 }
121 object_ref(obj);
122 return creds;
123}
124
125
Markus Armbrusterbd269eb2017-04-26 09:36:41 +0200126void nbd_server_start(SocketAddress *addr, const char *tls_creds,
Kevin Wolf1c8222b2020-09-24 17:26:54 +0200127 const char *tls_authz, uint32_t max_connections,
128 Error **errp)
Daniel P. Berrangeddffee32016-02-10 18:41:14 +0000129{
130 if (nbd_server) {
Paolo Bonzini6dd844d2012-08-22 16:43:07 +0200131 error_setg(errp, "NBD server already running");
132 return;
133 }
134
Daniel P. Berrangeddffee32016-02-10 18:41:14 +0000135 nbd_server = g_new0(NBDServerData, 1);
Kevin Wolf1c8222b2020-09-24 17:26:54 +0200136 nbd_server->max_connections = max_connections;
Daniel P. Berrange862172f2017-12-18 10:16:42 +0000137 nbd_server->listener = qio_net_listener_new();
138
139 qio_net_listener_set_name(nbd_server->listener,
140 "nbd-listener");
141
Eric Blake582d4212021-02-09 09:27:58 -0600142 /*
143 * Because this server is persistent, a backlog of SOMAXCONN is
144 * better than trying to size it to max_connections.
145 */
146 if (qio_net_listener_open_sync(nbd_server->listener, addr, SOMAXCONN,
147 errp) < 0) {
Daniel P. Berrangeddffee32016-02-10 18:41:14 +0000148 goto error;
Paolo Bonzini6dd844d2012-08-22 16:43:07 +0200149 }
Daniel P. Berrangeae398272016-02-10 18:41:03 +0000150
Markus Armbrusterbd269eb2017-04-26 09:36:41 +0200151 if (tls_creds) {
Daniel P. Berrangeddffee32016-02-10 18:41:14 +0000152 nbd_server->tlscreds = nbd_get_tls_creds(tls_creds, errp);
153 if (!nbd_server->tlscreds) {
154 goto error;
155 }
Daniel P. Berrangeddffee32016-02-10 18:41:14 +0000156 }
157
Daniel P. Berrange00019452019-02-27 16:20:34 +0000158 nbd_server->tlsauthz = g_strdup(tls_authz);
159
Kevin Wolf1c8222b2020-09-24 17:26:54 +0200160 nbd_update_server_watch(nbd_server);
Daniel P. Berrangeddffee32016-02-10 18:41:14 +0000161
162 return;
163
164 error:
165 nbd_server_free(nbd_server);
166 nbd_server = NULL;
Paolo Bonzini6dd844d2012-08-22 16:43:07 +0200167}
168
Kevin Wolfeed8b692020-02-24 15:29:57 +0100169void nbd_server_start_options(NbdServerOptions *arg, Error **errp)
170{
Kevin Wolf1c8222b2020-09-24 17:26:54 +0200171 nbd_server_start(arg->addr, arg->tls_creds, arg->tls_authz,
172 arg->max_connections, errp);
Kevin Wolfeed8b692020-02-24 15:29:57 +0100173}
174
Markus Armbrusterbd269eb2017-04-26 09:36:41 +0200175void qmp_nbd_server_start(SocketAddressLegacy *addr,
Markus Armbruster54fde4f2022-11-04 17:06:52 +0100176 const char *tls_creds,
177 const char *tls_authz,
Kevin Wolf1c8222b2020-09-24 17:26:54 +0200178 bool has_max_connections, uint32_t max_connections,
Markus Armbrusterbd269eb2017-04-26 09:36:41 +0200179 Error **errp)
180{
181 SocketAddress *addr_flat = socket_address_flatten(addr);
182
Kevin Wolf1c8222b2020-09-24 17:26:54 +0200183 nbd_server_start(addr_flat, tls_creds, tls_authz, max_connections, errp);
Markus Armbrusterbd269eb2017-04-26 09:36:41 +0200184 qapi_free_SocketAddress(addr_flat);
185}
186
Kevin Wolfb6076af2020-09-24 17:27:01 +0200187void qmp_nbd_server_add(NbdServerAddOptions *arg, Error **errp)
Kevin Wolf56ee8622020-09-24 17:26:50 +0200188{
Kevin Wolf9b562c62020-09-24 17:26:53 +0200189 BlockExport *export;
190 BlockDriverState *bs;
191 BlockBackend *on_eject_blk;
Kevin Wolfb6076af2020-09-24 17:27:01 +0200192 BlockExportOptions *export_opts;
Kevin Wolf9b562c62020-09-24 17:26:53 +0200193
194 bs = bdrv_lookup_bs(arg->device, arg->device, errp);
195 if (!bs) {
196 return;
197 }
198
Kevin Wolfb6076af2020-09-24 17:27:01 +0200199 /*
200 * block-export-add would default to the node-name, but we may have to use
201 * the device name as a default here for compatibility.
202 */
Markus Armbruster54fde4f2022-11-04 17:06:52 +0100203 if (!arg->name) {
Eric Blake8675cbd2020-10-27 00:05:48 -0500204 arg->name = g_strdup(arg->device);
Kevin Wolfb6076af2020-09-24 17:27:01 +0200205 }
206
207 export_opts = g_new(BlockExportOptions, 1);
208 *export_opts = (BlockExportOptions) {
209 .type = BLOCK_EXPORT_TYPE_NBD,
Kevin Wolfd53be9c2020-09-24 17:27:04 +0200210 .id = g_strdup(arg->name),
Kevin Wolfb6076af2020-09-24 17:27:01 +0200211 .node_name = g_strdup(bdrv_get_node_name(bs)),
Kevin Wolf30dbc812020-09-24 17:27:11 +0200212 .has_writable = arg->has_writable,
213 .writable = arg->writable,
Kevin Wolf56ee8622020-09-24 17:26:50 +0200214 };
Eric Blakecbad81c2020-10-27 00:05:49 -0500215 QAPI_CLONE_MEMBERS(BlockExportOptionsNbdBase, &export_opts->u.nbd,
Eric Blake8675cbd2020-10-27 00:05:48 -0500216 qapi_NbdServerAddOptions_base(arg));
Markus Armbruster54fde4f2022-11-04 17:06:52 +0100217 if (arg->bitmap) {
Vladimir Sementsov-Ogievskiye5fb29d2022-03-15 00:32:25 +0300218 BlockDirtyBitmapOrStr *el = g_new(BlockDirtyBitmapOrStr, 1);
219
220 *el = (BlockDirtyBitmapOrStr) {
221 .type = QTYPE_QSTRING,
222 .u.local = g_strdup(arg->bitmap),
223 };
Eric Blakecbad81c2020-10-27 00:05:49 -0500224 export_opts->u.nbd.has_bitmaps = true;
Vladimir Sementsov-Ogievskiye5fb29d2022-03-15 00:32:25 +0300225 QAPI_LIST_PREPEND(export_opts->u.nbd.bitmaps, el);
Eric Blakecbad81c2020-10-27 00:05:49 -0500226 }
Kevin Wolf9b562c62020-09-24 17:26:53 +0200227
228 /*
229 * nbd-server-add doesn't complain when a read-only device should be
230 * exported as writable, but simply downgrades it. This is an error with
231 * block-export-add.
232 */
233 if (bdrv_is_read_only(bs)) {
Kevin Wolf30dbc812020-09-24 17:27:11 +0200234 export_opts->has_writable = true;
235 export_opts->writable = false;
Kevin Wolf9b562c62020-09-24 17:26:53 +0200236 }
237
Kevin Wolfb6076af2020-09-24 17:27:01 +0200238 export = blk_exp_add(export_opts, errp);
Kevin Wolf9b562c62020-09-24 17:26:53 +0200239 if (!export) {
Kevin Wolfb6076af2020-09-24 17:27:01 +0200240 goto fail;
Kevin Wolf9b562c62020-09-24 17:26:53 +0200241 }
242
243 /*
244 * nbd-server-add removes the export when the named BlockBackend used for
245 * @device goes away.
246 */
247 on_eject_blk = blk_by_name(arg->device);
248 if (on_eject_blk) {
249 nbd_export_set_on_eject_blk(export, on_eject_blk);
250 }
Kevin Wolfb6076af2020-09-24 17:27:01 +0200251
252fail:
253 qapi_free_BlockExportOptions(export_opts);
Paolo Bonzini6dd844d2012-08-22 16:43:07 +0200254}
255
Vladimir Sementsov-Ogievskiya3b0dc72018-01-19 16:57:16 +0300256void qmp_nbd_server_remove(const char *name,
Kevin Wolf3c3bc462020-09-24 17:27:06 +0200257 bool has_mode, BlockExportRemoveMode mode,
Vladimir Sementsov-Ogievskiya3b0dc72018-01-19 16:57:16 +0300258 Error **errp)
259{
Kevin Wolf3c3bc462020-09-24 17:27:06 +0200260 BlockExport *exp;
Vladimir Sementsov-Ogievskiya3b0dc72018-01-19 16:57:16 +0300261
Kevin Wolf3c3bc462020-09-24 17:27:06 +0200262 exp = blk_exp_find(name);
263 if (exp && exp->drv->type != BLOCK_EXPORT_TYPE_NBD) {
264 error_setg(errp, "Block export '%s' is not an NBD export", name);
Vladimir Sementsov-Ogievskiya3b0dc72018-01-19 16:57:16 +0300265 return;
266 }
267
Kevin Wolf3c3bc462020-09-24 17:27:06 +0200268 qmp_block_export_del(name, has_mode, mode, errp);
Vladimir Sementsov-Ogievskiya3b0dc72018-01-19 16:57:16 +0300269}
270
Paolo Bonzini6dd844d2012-08-22 16:43:07 +0200271void qmp_nbd_server_stop(Error **errp)
272{
Eric Blake7801c3a2019-01-11 13:47:14 -0600273 if (!nbd_server) {
274 error_setg(errp, "NBD server not running");
275 return;
276 }
277
Kevin Wolfbc4ee652020-09-24 17:27:03 +0200278 blk_exp_close_all_type(BLOCK_EXPORT_TYPE_NBD);
Paolo Bonzini6dd844d2012-08-22 16:43:07 +0200279
Daniel P. Berrangeddffee32016-02-10 18:41:14 +0000280 nbd_server_free(nbd_server);
281 nbd_server = NULL;
Paolo Bonzini6dd844d2012-08-22 16:43:07 +0200282}