Merge remote-tracking branch 'remotes/mjt/tags/trivial-patches-fetch' into staging
[qemu.git] / blockdev-nbd.c
blob28f551a7b044b2c88128cf1a0630f55ecb83a291
1 /*
2 * Serving QEMU block devices via NBD
4 * Copyright (c) 2012 Red Hat, Inc.
6 * Author: Paolo Bonzini <pbonzini@redhat.com>
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.
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/qmp/qerror.h"
17 #include "sysemu/sysemu.h"
18 #include "qmp-commands.h"
19 #include "block/nbd.h"
20 #include "io/channel-socket.h"
22 typedef struct NBDServerData {
23 QIOChannelSocket *listen_ioc;
24 int watch;
25 QCryptoTLSCreds *tlscreds;
26 } NBDServerData;
28 static NBDServerData *nbd_server;
30 static void nbd_blockdev_client_closed(NBDClient *client, bool ignored)
32 nbd_client_put(client);
35 static gboolean nbd_accept(QIOChannel *ioc, GIOCondition condition,
36 gpointer opaque)
38 QIOChannelSocket *cioc;
40 if (!nbd_server) {
41 return FALSE;
44 cioc = qio_channel_socket_accept(QIO_CHANNEL_SOCKET(ioc),
45 NULL);
46 if (!cioc) {
47 return TRUE;
50 qio_channel_set_name(QIO_CHANNEL(cioc), "nbd-server");
51 nbd_client_new(NULL, cioc,
52 nbd_server->tlscreds, NULL,
53 nbd_blockdev_client_closed);
54 object_unref(OBJECT(cioc));
55 return TRUE;
59 static void nbd_server_free(NBDServerData *server)
61 if (!server) {
62 return;
65 if (server->watch != -1) {
66 g_source_remove(server->watch);
68 object_unref(OBJECT(server->listen_ioc));
69 if (server->tlscreds) {
70 object_unref(OBJECT(server->tlscreds));
73 g_free(server);
76 static QCryptoTLSCreds *nbd_get_tls_creds(const char *id, Error **errp)
78 Object *obj;
79 QCryptoTLSCreds *creds;
81 obj = object_resolve_path_component(
82 object_get_objects_root(), id);
83 if (!obj) {
84 error_setg(errp, "No TLS credentials with id '%s'",
85 id);
86 return NULL;
88 creds = (QCryptoTLSCreds *)
89 object_dynamic_cast(obj, TYPE_QCRYPTO_TLS_CREDS);
90 if (!creds) {
91 error_setg(errp, "Object with id '%s' is not TLS credentials",
92 id);
93 return NULL;
96 if (creds->endpoint != QCRYPTO_TLS_CREDS_ENDPOINT_SERVER) {
97 error_setg(errp,
98 "Expecting TLS credentials with a server endpoint");
99 return NULL;
101 object_ref(obj);
102 return creds;
106 void nbd_server_start(SocketAddress *addr, const char *tls_creds,
107 Error **errp)
109 if (nbd_server) {
110 error_setg(errp, "NBD server already running");
111 return;
114 nbd_server = g_new0(NBDServerData, 1);
115 nbd_server->watch = -1;
116 nbd_server->listen_ioc = qio_channel_socket_new();
117 qio_channel_set_name(QIO_CHANNEL(nbd_server->listen_ioc),
118 "nbd-listener");
119 if (qio_channel_socket_listen_sync(
120 nbd_server->listen_ioc, addr, errp) < 0) {
121 goto error;
124 if (tls_creds) {
125 nbd_server->tlscreds = nbd_get_tls_creds(tls_creds, errp);
126 if (!nbd_server->tlscreds) {
127 goto error;
130 /* TODO SOCKET_ADDRESS_TYPE_FD where fd has AF_INET or AF_INET6 */
131 if (addr->type != SOCKET_ADDRESS_TYPE_INET) {
132 error_setg(errp, "TLS is only supported with IPv4/IPv6");
133 goto error;
137 nbd_server->watch = qio_channel_add_watch(
138 QIO_CHANNEL(nbd_server->listen_ioc),
139 G_IO_IN,
140 nbd_accept,
141 NULL,
142 NULL);
144 return;
146 error:
147 nbd_server_free(nbd_server);
148 nbd_server = NULL;
151 void qmp_nbd_server_start(SocketAddressLegacy *addr,
152 bool has_tls_creds, const char *tls_creds,
153 Error **errp)
155 SocketAddress *addr_flat = socket_address_flatten(addr);
157 nbd_server_start(addr_flat, tls_creds, errp);
158 qapi_free_SocketAddress(addr_flat);
161 void qmp_nbd_server_add(const char *device, bool has_writable, bool writable,
162 Error **errp)
164 BlockDriverState *bs = NULL;
165 BlockBackend *on_eject_blk;
166 NBDExport *exp;
168 if (!nbd_server) {
169 error_setg(errp, "NBD server not running");
170 return;
173 if (nbd_export_find(device)) {
174 error_setg(errp, "NBD server already exporting device '%s'", device);
175 return;
178 on_eject_blk = blk_by_name(device);
180 bs = bdrv_lookup_bs(device, device, errp);
181 if (!bs) {
182 return;
185 if (!has_writable) {
186 writable = false;
188 if (bdrv_is_read_only(bs)) {
189 writable = false;
192 exp = nbd_export_new(bs, 0, -1, writable ? 0 : NBD_FLAG_READ_ONLY,
193 NULL, false, on_eject_blk, errp);
194 if (!exp) {
195 return;
198 nbd_export_set_name(exp, device);
200 /* The list of named exports has a strong reference to this export now and
201 * our only way of accessing it is through nbd_export_find(), so we can drop
202 * the strong reference that is @exp. */
203 nbd_export_put(exp);
206 void qmp_nbd_server_stop(Error **errp)
208 nbd_export_close_all();
210 nbd_server_free(nbd_server);
211 nbd_server = NULL;