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Commit | Line | Data |
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75818250 TS |
1 | /* |
2 | * QEMU Block driver for NBD | |
3 | * | |
4 | * Copyright (C) 2008 Bull S.A.S. | |
bd5921b4 | 5 | * Author: Laurent Vivier <Laurent.Vivier@bull.net> |
75818250 TS |
6 | * |
7 | * Some parts: | |
8 | * Copyright (C) 2007 Anthony Liguori <anthony@codemonkey.ws> | |
9 | * | |
10 | * Permission is hereby granted, free of charge, to any person obtaining a copy | |
11 | * of this software and associated documentation files (the "Software"), to deal | |
12 | * in the Software without restriction, including without limitation the rights | |
13 | * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell | |
14 | * copies of the Software, and to permit persons to whom the Software is | |
15 | * furnished to do so, subject to the following conditions: | |
16 | * | |
17 | * The above copyright notice and this permission notice shall be included in | |
18 | * all copies or substantial portions of the Software. | |
19 | * | |
20 | * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR | |
21 | * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, | |
22 | * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL | |
23 | * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER | |
24 | * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, | |
25 | * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN | |
26 | * THE SOFTWARE. | |
27 | */ | |
28 | ||
29 | #include "qemu-common.h" | |
30 | #include "nbd.h" | |
5efa9d5a | 31 | #include "module.h" |
33897dc7 | 32 | #include "qemu_socket.h" |
75818250 TS |
33 | |
34 | #include <sys/types.h> | |
35 | #include <unistd.h> | |
75818250 | 36 | |
1d45f8b5 LV |
37 | #define EN_OPTSTR ":exportname=" |
38 | ||
33897dc7 NT |
39 | /* #define DEBUG_NBD */ |
40 | ||
41 | #if defined(DEBUG_NBD) | |
42 | #define logout(fmt, ...) \ | |
43 | fprintf(stderr, "nbd\t%-24s" fmt, __func__, ##__VA_ARGS__) | |
44 | #else | |
45 | #define logout(fmt, ...) ((void)0) | |
46 | #endif | |
47 | ||
75818250 TS |
48 | typedef struct BDRVNBDState { |
49 | int sock; | |
50 | off_t size; | |
51 | size_t blocksize; | |
33897dc7 NT |
52 | char *export_name; /* An NBD server may export several devices */ |
53 | ||
54 | /* If it begins with '/', this is a UNIX domain socket. Otherwise, | |
55 | * it's a string of the form <hostname|ip4|\[ip6\]>:port | |
56 | */ | |
57 | char *host_spec; | |
75818250 TS |
58 | } BDRVNBDState; |
59 | ||
33897dc7 | 60 | static int nbd_config(BDRVNBDState *s, const char *filename, int flags) |
75818250 | 61 | { |
1d45f8b5 | 62 | char *file; |
33897dc7 NT |
63 | char *export_name; |
64 | const char *host_spec; | |
75818250 | 65 | const char *unixpath; |
1d45f8b5 | 66 | int err = -EINVAL; |
75818250 | 67 | |
7267c094 | 68 | file = g_strdup(filename); |
1d45f8b5 | 69 | |
33897dc7 NT |
70 | export_name = strstr(file, EN_OPTSTR); |
71 | if (export_name) { | |
72 | if (export_name[strlen(EN_OPTSTR)] == 0) { | |
1d45f8b5 LV |
73 | goto out; |
74 | } | |
33897dc7 NT |
75 | export_name[0] = 0; /* truncate 'file' */ |
76 | export_name += strlen(EN_OPTSTR); | |
7267c094 | 77 | s->export_name = g_strdup(export_name); |
1d45f8b5 LV |
78 | } |
79 | ||
33897dc7 NT |
80 | /* extract the host_spec - fail if it's not nbd:... */ |
81 | if (!strstart(file, "nbd:", &host_spec)) { | |
1d45f8b5 LV |
82 | goto out; |
83 | } | |
75818250 | 84 | |
33897dc7 NT |
85 | /* are we a UNIX or TCP socket? */ |
86 | if (strstart(host_spec, "unix:", &unixpath)) { | |
87 | if (unixpath[0] != '/') { /* We demand an absolute path*/ | |
1d45f8b5 LV |
88 | goto out; |
89 | } | |
7267c094 | 90 | s->host_spec = g_strdup(unixpath); |
75818250 | 91 | } else { |
7267c094 | 92 | s->host_spec = g_strdup(host_spec); |
33897dc7 | 93 | } |
75818250 | 94 | |
33897dc7 | 95 | err = 0; |
75818250 | 96 | |
33897dc7 | 97 | out: |
7267c094 | 98 | g_free(file); |
33897dc7 | 99 | if (err != 0) { |
7267c094 AL |
100 | g_free(s->export_name); |
101 | g_free(s->host_spec); | |
33897dc7 NT |
102 | } |
103 | return err; | |
104 | } | |
1d45f8b5 | 105 | |
33897dc7 NT |
106 | static int nbd_establish_connection(BlockDriverState *bs) |
107 | { | |
108 | BDRVNBDState *s = bs->opaque; | |
109 | int sock; | |
110 | int ret; | |
111 | off_t size; | |
112 | size_t blocksize; | |
113 | uint32_t nbdflags; | |
75818250 | 114 | |
33897dc7 NT |
115 | if (s->host_spec[0] == '/') { |
116 | sock = unix_socket_outgoing(s->host_spec); | |
117 | } else { | |
118 | sock = tcp_socket_outgoing_spec(s->host_spec); | |
75818250 TS |
119 | } |
120 | ||
33897dc7 | 121 | /* Failed to establish connection */ |
1d45f8b5 | 122 | if (sock == -1) { |
33897dc7 NT |
123 | logout("Failed to establish connection to NBD server\n"); |
124 | return -errno; | |
1d45f8b5 | 125 | } |
75818250 | 126 | |
33897dc7 NT |
127 | /* NBD handshake */ |
128 | ret = nbd_receive_negotiate(sock, s->export_name, &nbdflags, &size, | |
129 | &blocksize); | |
1d45f8b5 | 130 | if (ret == -1) { |
33897dc7 NT |
131 | logout("Failed to negotiate with the NBD server\n"); |
132 | closesocket(sock); | |
133 | return -errno; | |
1d45f8b5 | 134 | } |
75818250 | 135 | |
33897dc7 NT |
136 | /* Now that we're connected, set the socket to be non-blocking */ |
137 | socket_set_nonblock(sock); | |
138 | ||
75818250 TS |
139 | s->sock = sock; |
140 | s->size = size; | |
141 | s->blocksize = blocksize; | |
142 | ||
33897dc7 NT |
143 | logout("Established connection with NBD server\n"); |
144 | return 0; | |
145 | } | |
146 | ||
147 | static void nbd_teardown_connection(BlockDriverState *bs) | |
148 | { | |
149 | BDRVNBDState *s = bs->opaque; | |
150 | struct nbd_request request; | |
151 | ||
152 | request.type = NBD_CMD_DISC; | |
153 | request.handle = (uint64_t)(intptr_t)bs; | |
154 | request.from = 0; | |
155 | request.len = 0; | |
156 | nbd_send_request(s->sock, &request); | |
157 | ||
158 | closesocket(s->sock); | |
159 | } | |
160 | ||
161 | static int nbd_open(BlockDriverState *bs, const char* filename, int flags) | |
162 | { | |
163 | BDRVNBDState *s = bs->opaque; | |
164 | int result; | |
165 | ||
166 | /* Pop the config into our state object. Exit if invalid. */ | |
167 | result = nbd_config(s, filename, flags); | |
168 | if (result != 0) { | |
169 | return result; | |
170 | } | |
171 | ||
172 | /* establish TCP connection, return error if it fails | |
173 | * TODO: Configurable retry-until-timeout behaviour. | |
174 | */ | |
175 | result = nbd_establish_connection(bs); | |
176 | ||
177 | return result; | |
75818250 TS |
178 | } |
179 | ||
180 | static int nbd_read(BlockDriverState *bs, int64_t sector_num, | |
181 | uint8_t *buf, int nb_sectors) | |
182 | { | |
183 | BDRVNBDState *s = bs->opaque; | |
184 | struct nbd_request request; | |
185 | struct nbd_reply reply; | |
186 | ||
187 | request.type = NBD_CMD_READ; | |
188 | request.handle = (uint64_t)(intptr_t)bs; | |
189 | request.from = sector_num * 512;; | |
190 | request.len = nb_sectors * 512; | |
191 | ||
192 | if (nbd_send_request(s->sock, &request) == -1) | |
193 | return -errno; | |
194 | ||
195 | if (nbd_receive_reply(s->sock, &reply) == -1) | |
196 | return -errno; | |
197 | ||
198 | if (reply.error !=0) | |
199 | return -reply.error; | |
200 | ||
201 | if (reply.handle != request.handle) | |
202 | return -EIO; | |
203 | ||
204 | if (nbd_wr_sync(s->sock, buf, request.len, 1) != request.len) | |
205 | return -EIO; | |
206 | ||
207 | return 0; | |
208 | } | |
209 | ||
210 | static int nbd_write(BlockDriverState *bs, int64_t sector_num, | |
211 | const uint8_t *buf, int nb_sectors) | |
212 | { | |
213 | BDRVNBDState *s = bs->opaque; | |
214 | struct nbd_request request; | |
215 | struct nbd_reply reply; | |
216 | ||
217 | request.type = NBD_CMD_WRITE; | |
218 | request.handle = (uint64_t)(intptr_t)bs; | |
219 | request.from = sector_num * 512;; | |
220 | request.len = nb_sectors * 512; | |
221 | ||
222 | if (nbd_send_request(s->sock, &request) == -1) | |
223 | return -errno; | |
224 | ||
225 | if (nbd_wr_sync(s->sock, (uint8_t*)buf, request.len, 0) != request.len) | |
226 | return -EIO; | |
227 | ||
228 | if (nbd_receive_reply(s->sock, &reply) == -1) | |
229 | return -errno; | |
230 | ||
231 | if (reply.error !=0) | |
232 | return -reply.error; | |
233 | ||
234 | if (reply.handle != request.handle) | |
235 | return -EIO; | |
236 | ||
237 | return 0; | |
238 | } | |
239 | ||
240 | static void nbd_close(BlockDriverState *bs) | |
241 | { | |
d2d979c6 | 242 | BDRVNBDState *s = bs->opaque; |
7267c094 AL |
243 | g_free(s->export_name); |
244 | g_free(s->host_spec); | |
d2d979c6 | 245 | |
33897dc7 | 246 | nbd_teardown_connection(bs); |
75818250 TS |
247 | } |
248 | ||
249 | static int64_t nbd_getlength(BlockDriverState *bs) | |
250 | { | |
251 | BDRVNBDState *s = bs->opaque; | |
252 | ||
253 | return s->size; | |
254 | } | |
255 | ||
5efa9d5a | 256 | static BlockDriver bdrv_nbd = { |
e60f469c AJ |
257 | .format_name = "nbd", |
258 | .instance_size = sizeof(BDRVNBDState), | |
66f82cee | 259 | .bdrv_file_open = nbd_open, |
e60f469c AJ |
260 | .bdrv_read = nbd_read, |
261 | .bdrv_write = nbd_write, | |
262 | .bdrv_close = nbd_close, | |
263 | .bdrv_getlength = nbd_getlength, | |
264 | .protocol_name = "nbd", | |
75818250 | 265 | }; |
5efa9d5a AL |
266 | |
267 | static void bdrv_nbd_init(void) | |
268 | { | |
269 | bdrv_register(&bdrv_nbd); | |
270 | } | |
271 | ||
272 | block_init(bdrv_nbd_init); |