![[BACK]](/cvsweb/icons/back.gif){kind=icon}
Return to nbd.c CVS log ![[TXT]](/cvsweb/icons/text.gif){kind=icon}
![[DIR]](/cvsweb/icons/dir.gif){kind=icon}
Up to [Qemu by Fabrice Bellard] / qemu / block|
Return to nbd.c CVS log | Up to [Qemu by Fabrice Bellard] / qemu / block |
1.1 root 1: /*
2: * QEMU Block driver for NBD
3: *
4: * Copyright (C) 2008 Bull S.A.S.
5: * Author: Laurent Vivier <[email protected]>
6: *
7: * Some parts:
8: * Copyright (C) 2007 Anthony Liguori <[email protected]>
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"
31: #include "module.h"
1.1.1.4 ! root 32: #include "qemu_socket.h"
1.1 root 33:
34: #include <sys/types.h>
35: #include <unistd.h>
36:
1.1.1.3 root 37: #define EN_OPTSTR ":exportname="
38:
1.1.1.4 ! root 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:
1.1 root 48: typedef struct BDRVNBDState {
49: int sock;
50: off_t size;
51: size_t blocksize;
1.1.1.4 ! root 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;
1.1 root 58: } BDRVNBDState;
59:
1.1.1.4 ! root 60: static int nbd_config(BDRVNBDState *s, const char *filename, int flags)
1.1 root 61: {
1.1.1.3 root 62: char *file;
1.1.1.4 ! root 63: char *export_name;
! 64: const char *host_spec;
1.1 root 65: const char *unixpath;
1.1.1.3 root 66: int err = -EINVAL;
67:
68: file = qemu_strdup(filename);
1.1 root 69:
1.1.1.4 ! root 70: export_name = strstr(file, EN_OPTSTR);
! 71: if (export_name) {
! 72: if (export_name[strlen(EN_OPTSTR)] == 0) {
1.1.1.3 root 73: goto out;
74: }
1.1.1.4 ! root 75: export_name[0] = 0; /* truncate 'file' */
! 76: export_name += strlen(EN_OPTSTR);
! 77: s->export_name = qemu_strdup(export_name);
1.1.1.3 root 78: }
79:
1.1.1.4 ! root 80: /* extract the host_spec - fail if it's not nbd:... */
! 81: if (!strstart(file, "nbd:", &host_spec)) {
1.1.1.3 root 82: goto out;
83: }
1.1 root 84:
1.1.1.4 ! root 85: /* are we a UNIX or TCP socket? */
! 86: if (strstart(host_spec, "unix:", &unixpath)) {
! 87: if (unixpath[0] != '/') { /* We demand an absolute path*/
1.1.1.3 root 88: goto out;
89: }
1.1.1.4 ! root 90: s->host_spec = qemu_strdup(unixpath);
! 91: } else {
! 92: s->host_spec = qemu_strdup(host_spec);
! 93: }
1.1 root 94:
1.1.1.4 ! root 95: err = 0;
1.1 root 96:
1.1.1.4 ! root 97: out:
! 98: qemu_free(file);
! 99: if (err != 0) {
! 100: qemu_free(s->export_name);
! 101: qemu_free(s->host_spec);
! 102: }
! 103: return err;
! 104: }
1.1 root 105:
1.1.1.4 ! root 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;
! 114:
! 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);
1.1 root 119: }
120:
1.1.1.4 ! root 121: /* Failed to establish connection */
1.1.1.3 root 122: if (sock == -1) {
1.1.1.4 ! root 123: logout("Failed to establish connection to NBD server\n");
! 124: return -errno;
1.1.1.3 root 125: }
1.1 root 126:
1.1.1.4 ! root 127: /* NBD handshake */
! 128: ret = nbd_receive_negotiate(sock, s->export_name, &nbdflags, &size,
! 129: &blocksize);
1.1.1.3 root 130: if (ret == -1) {
1.1.1.4 ! root 131: logout("Failed to negotiate with the NBD server\n");
! 132: closesocket(sock);
! 133: return -errno;
1.1.1.3 root 134: }
1.1 root 135:
1.1.1.4 ! root 136: /* Now that we're connected, set the socket to be non-blocking */
! 137: socket_set_nonblock(sock);
! 138:
1.1 root 139: s->sock = sock;
140: s->size = size;
141: s->blocksize = blocksize;
142:
1.1.1.4 ! root 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;
1.1 root 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: {
242: BDRVNBDState *s = bs->opaque;
1.1.1.4 ! root 243: qemu_free(s->export_name);
! 244: qemu_free(s->host_spec);
1.1 root 245:
1.1.1.4 ! root 246: nbd_teardown_connection(bs);
1.1 root 247: }
248:
249: static int64_t nbd_getlength(BlockDriverState *bs)
250: {
251: BDRVNBDState *s = bs->opaque;
252:
253: return s->size;
254: }
255:
256: static BlockDriver bdrv_nbd = {
257: .format_name = "nbd",
258: .instance_size = sizeof(BDRVNBDState),
1.1.1.2 root 259: .bdrv_file_open = nbd_open,
1.1 root 260: .bdrv_read = nbd_read,
261: .bdrv_write = nbd_write,
262: .bdrv_close = nbd_close,
263: .bdrv_getlength = nbd_getlength,
264: .protocol_name = "nbd",
265: };
266:
267: static void bdrv_nbd_init(void)
268: {
269: bdrv_register(&bdrv_nbd);
270: }
271:
272: block_init(bdrv_nbd_init);
This archive runs on limited infrastructure. Preserving old code on modern bandwidth. Automated agents are requested to crawl responsibly.