xref: /openbmc/qemu/include/block/nbd.h (revision 1fd6bb44)
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 #include "qemu/option.h"
26 
27 struct nbd_request {
28     uint32_t magic;
29     uint32_t type;
30     uint64_t handle;
31     uint64_t from;
32     uint32_t len;
33 } QEMU_PACKED;
34 
35 struct nbd_reply {
36     uint32_t magic;
37     uint32_t error;
38     uint64_t handle;
39 } QEMU_PACKED;
40 
41 #define NBD_FLAG_HAS_FLAGS      (1 << 0)        /* Flags are there */
42 #define NBD_FLAG_READ_ONLY      (1 << 1)        /* Device is read-only */
43 #define NBD_FLAG_SEND_FLUSH     (1 << 2)        /* Send FLUSH */
44 #define NBD_FLAG_SEND_FUA       (1 << 3)        /* Send FUA (Force Unit Access) */
45 #define NBD_FLAG_ROTATIONAL     (1 << 4)        /* Use elevator algorithm - rotational media */
46 #define NBD_FLAG_SEND_TRIM      (1 << 5)        /* Send TRIM (discard) */
47 
48 #define NBD_CMD_MASK_COMMAND	0x0000ffff
49 #define NBD_CMD_FLAG_FUA	(1 << 16)
50 
51 enum {
52     NBD_CMD_READ = 0,
53     NBD_CMD_WRITE = 1,
54     NBD_CMD_DISC = 2,
55     NBD_CMD_FLUSH = 3,
56     NBD_CMD_TRIM = 4
57 };
58 
59 #define NBD_DEFAULT_PORT	10809
60 
61 #define NBD_BUFFER_SIZE (1024*1024)
62 
63 ssize_t nbd_wr_sync(int fd, void *buffer, size_t size, bool do_read);
64 int tcp_socket_incoming(const char *address, uint16_t port);
65 int tcp_socket_incoming_spec(const char *address_and_port);
66 int tcp_socket_outgoing_opts(QemuOpts *opts);
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 ssize_t nbd_send_request(int csock, struct nbd_request *request);
74 ssize_t 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 (*close)(NBDExport *));
84 void nbd_export_close(NBDExport *exp);
85 void nbd_export_get(NBDExport *exp);
86 void nbd_export_put(NBDExport *exp);
87 
88 BlockDriverState *nbd_export_get_blockdev(NBDExport *exp);
89 
90 NBDExport *nbd_export_find(const char *name);
91 void nbd_export_set_name(NBDExport *exp, const char *name);
92 void nbd_export_close_all(void);
93 
94 NBDClient *nbd_client_new(NBDExport *exp, int csock,
95                           void (*close)(NBDClient *));
96 void nbd_client_close(NBDClient *client);
97 void nbd_client_get(NBDClient *client);
98 void nbd_client_put(NBDClient *client);
99 
100 #endif
101