aboutsummaryrefslogtreecommitdiff
path: root/blockdev-nbd.c
blob: 65a84739edc7ec005a62b33f074e61352217a682 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
/*
 * Serving QEMU block devices via NBD
 *
 * Copyright (c) 2012 Red Hat, Inc.
 *
 * Author: Paolo Bonzini <pbonzini@redhat.com>
 *
 * This work is licensed under the terms of the GNU GPL, version 2 or
 * later.  See the COPYING file in the top-level directory.
 */

#include "qemu/osdep.h"
#include "sysemu/blockdev.h"
#include "sysemu/block-backend.h"
#include "hw/block/block.h"
#include "qapi/error.h"
#include "qapi/qapi-commands-block.h"
#include "sysemu/sysemu.h"
#include "block/nbd.h"
#include "io/channel-socket.h"
#include "io/net-listener.h"

typedef struct NBDServerData {
    QIONetListener *listener;
    QCryptoTLSCreds *tlscreds;
} NBDServerData;

static NBDServerData *nbd_server;

static void nbd_blockdev_client_closed(NBDClient *client, bool ignored)
{
    nbd_client_put(client);
}

static void nbd_accept(QIONetListener *listener, QIOChannelSocket *cioc,
                       gpointer opaque)
{
    qio_channel_set_name(QIO_CHANNEL(cioc), "nbd-server");
    nbd_client_new(NULL, cioc,
                   nbd_server->tlscreds, NULL,
                   nbd_blockdev_client_closed);
}


static void nbd_server_free(NBDServerData *server)
{
    if (!server) {
        return;
    }

    qio_net_listener_disconnect(server->listener);
    object_unref(OBJECT(server->listener));
    if (server->tlscreds) {
        object_unref(OBJECT(server->tlscreds));
    }

    g_free(server);
}

static QCryptoTLSCreds *nbd_get_tls_creds(const char *id, Error **errp)
{
    Object *obj;
    QCryptoTLSCreds *creds;

    obj = object_resolve_path_component(
        object_get_objects_root(), id);
    if (!obj) {
        error_setg(errp, "No TLS credentials with id '%s'",
                   id);
        return NULL;
    }
    creds = (QCryptoTLSCreds *)
        object_dynamic_cast(obj, TYPE_QCRYPTO_TLS_CREDS);
    if (!creds) {
        error_setg(errp, "Object with id '%s' is not TLS credentials",
                   id);
        return NULL;
    }

    if (creds->endpoint != QCRYPTO_TLS_CREDS_ENDPOINT_SERVER) {
        error_setg(errp,
                   "Expecting TLS credentials with a server endpoint");
        return NULL;
    }
    object_ref(obj);
    return creds;
}


void nbd_server_start(SocketAddress *addr, const char *tls_creds,
                      Error **errp)
{
    if (nbd_server) {
        error_setg(errp, "NBD server already running");
        return;
    }

    nbd_server = g_new0(NBDServerData, 1);
    nbd_server->listener = qio_net_listener_new();

    qio_net_listener_set_name(nbd_server->listener,
                              "nbd-listener");

    if (qio_net_listener_open_sync(nbd_server->listener, addr, errp) < 0) {
        goto error;
    }

    if (tls_creds) {
        nbd_server->tlscreds = nbd_get_tls_creds(tls_creds, errp);
        if (!nbd_server->tlscreds) {
            goto error;
        }

        /* TODO SOCKET_ADDRESS_TYPE_FD where fd has AF_INET or AF_INET6 */
        if (addr->type != SOCKET_ADDRESS_TYPE_INET) {
            error_setg(errp, "TLS is only supported with IPv4/IPv6");
            goto error;
        }
    }

    qio_net_listener_set_client_func(nbd_server->listener,
                                     nbd_accept,
                                     NULL,
                                     NULL);

    return;

 error:
    nbd_server_free(nbd_server);
    nbd_server = NULL;
}

void qmp_nbd_server_start(SocketAddressLegacy *addr,
                          bool has_tls_creds, const char *tls_creds,
                          Error **errp)
{
    SocketAddress *addr_flat = socket_address_flatten(addr);

    nbd_server_start(addr_flat, tls_creds, errp);
    qapi_free_SocketAddress(addr_flat);
}

void qmp_nbd_server_add(const char *device, bool has_name, const char *name,
                        bool has_writable, bool writable, Error **errp)
{
    BlockDriverState *bs = NULL;
    BlockBackend *on_eject_blk;
    NBDExport *exp;

    if (!nbd_server) {
        error_setg(errp, "NBD server not running");
        return;
    }

    if (!has_name) {
        name = device;
    }

    if (nbd_export_find(name)) {
        error_setg(errp, "NBD server already has export named '%s'", name);
        return;
    }

    on_eject_blk = blk_by_name(device);

    bs = bdrv_lookup_bs(device, device, errp);
    if (!bs) {
        return;
    }

    if (!has_writable) {
        writable = false;
    }
    if (bdrv_is_read_only(bs)) {
        writable = false;
    }

    exp = nbd_export_new(bs, 0, -1, writable ? 0 : NBD_FLAG_READ_ONLY,
                         NULL, false, on_eject_blk, errp);
    if (!exp) {
        return;
    }

    nbd_export_set_name(exp, name);

    /* The list of named exports has a strong reference to this export now and
     * our only way of accessing it is through nbd_export_find(), so we can drop
     * the strong reference that is @exp. */
    nbd_export_put(exp);
}

void qmp_nbd_server_remove(const char *name,
                           bool has_mode, NbdServerRemoveMode mode,
                           Error **errp)
{
    NBDExport *exp;

    if (!nbd_server) {
        error_setg(errp, "NBD server not running");
        return;
    }

    exp = nbd_export_find(name);
    if (exp == NULL) {
        error_setg(errp, "Export '%s' is not found", name);
        return;
    }

    if (!has_mode) {
        mode = NBD_SERVER_REMOVE_MODE_SAFE;
    }

    nbd_export_remove(exp, mode, errp);
}

void qmp_nbd_server_stop(Error **errp)
{
    nbd_export_close_all();

    nbd_server_free(nbd_server);
    nbd_server = NULL;
}