vga: improve documentation
[qemu.git] / nbd.h
1 /*
2 * Copyright (C) 2005 Anthony Liguori <anthony@codemonkey.ws>
3 *
4 * Network Block Device
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; under version 2 of the License.
9 *
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
14 *
15 * You should have received a copy of the GNU General Public License
16 * along with this program; if not, see <http://www.gnu.org/licenses/>.
17 */
18
19 #ifndef NBD_H
20 #define NBD_H
21
22 #include <sys/types.h>
23
24 #include "qemu-common.h"
25
26 struct nbd_request {
27 uint32_t magic;
28 uint32_t type;
29 uint64_t handle;
30 uint64_t from;
31 uint32_t len;
32 } QEMU_PACKED;
33
34 struct nbd_reply {
35 uint32_t magic;
36 uint32_t error;
37 uint64_t handle;
38 } QEMU_PACKED;
39
40 #define NBD_FLAG_HAS_FLAGS (1 << 0) /* Flags are there */
41 #define NBD_FLAG_READ_ONLY (1 << 1) /* Device is read-only */
42 #define NBD_FLAG_SEND_FLUSH (1 << 2) /* Send FLUSH */
43 #define NBD_FLAG_SEND_FUA (1 << 3) /* Send FUA (Force Unit Access) */
44 #define NBD_FLAG_ROTATIONAL (1 << 4) /* Use elevator algorithm - rotational media */
45 #define NBD_FLAG_SEND_TRIM (1 << 5) /* Send TRIM (discard) */
46
47 #define NBD_CMD_MASK_COMMAND 0x0000ffff
48 #define NBD_CMD_FLAG_FUA (1 << 16)
49
50 enum {
51 NBD_CMD_READ = 0,
52 NBD_CMD_WRITE = 1,
53 NBD_CMD_DISC = 2,
54 NBD_CMD_FLUSH = 3,
55 NBD_CMD_TRIM = 4
56 };
57
58 #define NBD_DEFAULT_PORT 10809
59
60 #define NBD_BUFFER_SIZE (1024*1024)
61
62 size_t nbd_wr_sync(int fd, void *buffer, size_t size, bool do_read);
63 int tcp_socket_outgoing(const char *address, uint16_t port);
64 int tcp_socket_incoming(const char *address, uint16_t port);
65 int tcp_socket_outgoing_spec(const char *address_and_port);
66 int tcp_socket_incoming_spec(const char *address_and_port);
67 int unix_socket_outgoing(const char *path);
68 int unix_socket_incoming(const char *path);
69
70 int nbd_receive_negotiate(int csock, const char *name, uint32_t *flags,
71 off_t *size, size_t *blocksize);
72 int nbd_init(int fd, int csock, uint32_t flags, off_t size, size_t blocksize);
73 int nbd_send_request(int csock, struct nbd_request *request);
74 int nbd_receive_reply(int csock, struct nbd_reply *reply);
75 int nbd_client(int fd);
76 int nbd_disconnect(int fd);
77
78 typedef struct NBDExport NBDExport;
79 typedef struct NBDClient NBDClient;
80
81 NBDExport *nbd_export_new(BlockDriverState *bs, off_t dev_offset,
82 off_t size, uint32_t nbdflags);
83 void nbd_export_close(NBDExport *exp);
84 NBDClient *nbd_client_new(NBDExport *exp, int csock,
85 void (*close)(NBDClient *));
86
87 #endif