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/qapi-commands-block.h" |
18 | #include "block/nbd.h" |
19 | #include "io/channel-socket.h" |
20 | #include "io/net-listener.h" |
21 | |
22 | typedef struct NBDServerData { |
23 | QIONetListener *listener; |
24 | QCryptoTLSCreds *tlscreds; |
25 | char *tlsauthz; |
26 | } NBDServerData; |
27 | |
28 | static NBDServerData *nbd_server; |
29 | |
30 | static void nbd_blockdev_client_closed(NBDClient *client, bool ignored) |
31 | { |
32 | nbd_client_put(client); |
33 | } |
34 | |
35 | static void nbd_accept(QIONetListener *listener, QIOChannelSocket *cioc, |
36 | gpointer opaque) |
37 | { |
38 | qio_channel_set_name(QIO_CHANNEL(cioc), "nbd-server" ); |
39 | nbd_client_new(cioc, nbd_server->tlscreds, nbd_server->tlsauthz, |
40 | nbd_blockdev_client_closed); |
41 | } |
42 | |
43 | |
44 | static void nbd_server_free(NBDServerData *server) |
45 | { |
46 | if (!server) { |
47 | return; |
48 | } |
49 | |
50 | qio_net_listener_disconnect(server->listener); |
51 | object_unref(OBJECT(server->listener)); |
52 | if (server->tlscreds) { |
53 | object_unref(OBJECT(server->tlscreds)); |
54 | } |
55 | g_free(server->tlsauthz); |
56 | |
57 | g_free(server); |
58 | } |
59 | |
60 | static QCryptoTLSCreds *nbd_get_tls_creds(const char *id, Error **errp) |
61 | { |
62 | Object *obj; |
63 | QCryptoTLSCreds *creds; |
64 | |
65 | obj = object_resolve_path_component( |
66 | object_get_objects_root(), id); |
67 | if (!obj) { |
68 | error_setg(errp, "No TLS credentials with id '%s'" , |
69 | id); |
70 | return NULL; |
71 | } |
72 | creds = (QCryptoTLSCreds *) |
73 | object_dynamic_cast(obj, TYPE_QCRYPTO_TLS_CREDS); |
74 | if (!creds) { |
75 | error_setg(errp, "Object with id '%s' is not TLS credentials" , |
76 | id); |
77 | return NULL; |
78 | } |
79 | |
80 | if (creds->endpoint != QCRYPTO_TLS_CREDS_ENDPOINT_SERVER) { |
81 | error_setg(errp, |
82 | "Expecting TLS credentials with a server endpoint" ); |
83 | return NULL; |
84 | } |
85 | object_ref(obj); |
86 | return creds; |
87 | } |
88 | |
89 | |
90 | void nbd_server_start(SocketAddress *addr, const char *tls_creds, |
91 | const char *tls_authz, Error **errp) |
92 | { |
93 | if (nbd_server) { |
94 | error_setg(errp, "NBD server already running" ); |
95 | return; |
96 | } |
97 | |
98 | nbd_server = g_new0(NBDServerData, 1); |
99 | nbd_server->listener = qio_net_listener_new(); |
100 | |
101 | qio_net_listener_set_name(nbd_server->listener, |
102 | "nbd-listener" ); |
103 | |
104 | if (qio_net_listener_open_sync(nbd_server->listener, addr, 1, errp) < 0) { |
105 | goto error; |
106 | } |
107 | |
108 | if (tls_creds) { |
109 | nbd_server->tlscreds = nbd_get_tls_creds(tls_creds, errp); |
110 | if (!nbd_server->tlscreds) { |
111 | goto error; |
112 | } |
113 | |
114 | /* TODO SOCKET_ADDRESS_TYPE_FD where fd has AF_INET or AF_INET6 */ |
115 | if (addr->type != SOCKET_ADDRESS_TYPE_INET) { |
116 | error_setg(errp, "TLS is only supported with IPv4/IPv6" ); |
117 | goto error; |
118 | } |
119 | } |
120 | |
121 | nbd_server->tlsauthz = g_strdup(tls_authz); |
122 | |
123 | qio_net_listener_set_client_func(nbd_server->listener, |
124 | nbd_accept, |
125 | NULL, |
126 | NULL); |
127 | |
128 | return; |
129 | |
130 | error: |
131 | nbd_server_free(nbd_server); |
132 | nbd_server = NULL; |
133 | } |
134 | |
135 | void qmp_nbd_server_start(SocketAddressLegacy *addr, |
136 | bool has_tls_creds, const char *tls_creds, |
137 | bool has_tls_authz, const char *tls_authz, |
138 | Error **errp) |
139 | { |
140 | SocketAddress *addr_flat = socket_address_flatten(addr); |
141 | |
142 | nbd_server_start(addr_flat, tls_creds, tls_authz, errp); |
143 | qapi_free_SocketAddress(addr_flat); |
144 | } |
145 | |
146 | void qmp_nbd_server_add(const char *device, bool has_name, const char *name, |
147 | bool has_writable, bool writable, |
148 | bool has_bitmap, const char *bitmap, Error **errp) |
149 | { |
150 | BlockDriverState *bs = NULL; |
151 | BlockBackend *on_eject_blk; |
152 | NBDExport *exp; |
153 | int64_t len; |
154 | |
155 | if (!nbd_server) { |
156 | error_setg(errp, "NBD server not running" ); |
157 | return; |
158 | } |
159 | |
160 | if (!has_name) { |
161 | name = device; |
162 | } |
163 | |
164 | if (nbd_export_find(name)) { |
165 | error_setg(errp, "NBD server already has export named '%s'" , name); |
166 | return; |
167 | } |
168 | |
169 | on_eject_blk = blk_by_name(device); |
170 | |
171 | bs = bdrv_lookup_bs(device, device, errp); |
172 | if (!bs) { |
173 | return; |
174 | } |
175 | |
176 | len = bdrv_getlength(bs); |
177 | if (len < 0) { |
178 | error_setg_errno(errp, -len, |
179 | "Failed to determine the NBD export's length" ); |
180 | return; |
181 | } |
182 | |
183 | if (!has_writable) { |
184 | writable = false; |
185 | } |
186 | if (bdrv_is_read_only(bs)) { |
187 | writable = false; |
188 | } |
189 | |
190 | exp = nbd_export_new(bs, 0, len, name, NULL, bitmap, |
191 | writable ? 0 : NBD_FLAG_READ_ONLY, |
192 | NULL, false, on_eject_blk, errp); |
193 | if (!exp) { |
194 | return; |
195 | } |
196 | |
197 | /* The list of named exports has a strong reference to this export now and |
198 | * our only way of accessing it is through nbd_export_find(), so we can drop |
199 | * the strong reference that is @exp. */ |
200 | nbd_export_put(exp); |
201 | } |
202 | |
203 | void qmp_nbd_server_remove(const char *name, |
204 | bool has_mode, NbdServerRemoveMode mode, |
205 | Error **errp) |
206 | { |
207 | NBDExport *exp; |
208 | |
209 | if (!nbd_server) { |
210 | error_setg(errp, "NBD server not running" ); |
211 | return; |
212 | } |
213 | |
214 | exp = nbd_export_find(name); |
215 | if (exp == NULL) { |
216 | error_setg(errp, "Export '%s' is not found" , name); |
217 | return; |
218 | } |
219 | |
220 | if (!has_mode) { |
221 | mode = NBD_SERVER_REMOVE_MODE_SAFE; |
222 | } |
223 | |
224 | nbd_export_remove(exp, mode, errp); |
225 | } |
226 | |
227 | void qmp_nbd_server_stop(Error **errp) |
228 | { |
229 | if (!nbd_server) { |
230 | error_setg(errp, "NBD server not running" ); |
231 | return; |
232 | } |
233 | |
234 | nbd_export_close_all(); |
235 | |
236 | nbd_server_free(nbd_server); |
237 | nbd_server = NULL; |
238 | } |
239 | |