1 #ifndef __DRBD_PROTOCOL_H
2 #define __DRBD_PROTOCOL_H
5 /* receiver (data socket) */
7 P_DATA_REPLY = 0x01, /* Response to P_DATA_REQUEST */
8 P_RS_DATA_REPLY = 0x02, /* Response to P_RS_DATA_REQUEST */
11 P_BECOME_SYNC_TARGET = 0x05,
12 P_BECOME_SYNC_SOURCE = 0x06,
13 P_UNPLUG_REMOTE = 0x07, /* Used at various times to hint the peer */
14 P_DATA_REQUEST = 0x08, /* Used to ask for a data block */
15 P_RS_DATA_REQUEST = 0x09, /* Used to ask for a data block for resync */
22 P_AUTH_CHALLENGE = 0x10,
23 P_AUTH_RESPONSE = 0x11,
24 P_STATE_CHG_REQ = 0x12,
29 P_RECV_ACK = 0x15, /* Used in protocol B */
30 P_WRITE_ACK = 0x16, /* Used in protocol C */
31 P_RS_WRITE_ACK = 0x17, /* Is a P_WRITE_ACK, additionally call set_in_sync(). */
32 P_SUPERSEDED = 0x18, /* Used in proto C, two-primaries conflict detection */
33 P_NEG_ACK = 0x19, /* Sent if local disk is unusable */
34 P_NEG_DREPLY = 0x1a, /* Local disk is broken... */
35 P_NEG_RS_DREPLY = 0x1b, /* Local disk is broken... */
37 P_STATE_CHG_REPLY = 0x1d,
39 /* "new" commands, no longer fitting into the ordering scheme above */
41 P_OV_REQUEST = 0x1e, /* data socket */
43 P_OV_RESULT = 0x20, /* meta socket */
44 P_CSUM_RS_REQUEST = 0x21, /* data socket */
45 P_RS_IS_IN_SYNC = 0x22, /* meta socket */
46 P_SYNC_PARAM89 = 0x23, /* data socket, protocol version 89 replacement for P_SYNC_PARAM */
47 P_COMPRESSED_BITMAP = 0x24, /* compressed or otherwise encoded bitmap transfer */
48 /* P_CKPT_FENCE_REQ = 0x25, * currently reserved for protocol D */
49 /* P_CKPT_DISABLE_REQ = 0x26, * currently reserved for protocol D */
50 P_DELAY_PROBE = 0x27, /* is used on BOTH sockets */
51 P_OUT_OF_SYNC = 0x28, /* Mark as out of sync (Outrunning), data socket */
52 P_RS_CANCEL = 0x29, /* meta: Used to cancel RS_DATA_REQUEST packet by SyncSource */
53 P_CONN_ST_CHG_REQ = 0x2a, /* data sock: Connection wide state request */
54 P_CONN_ST_CHG_REPLY = 0x2b, /* meta sock: Connection side state req reply */
55 P_RETRY_WRITE = 0x2c, /* Protocol C: retry conflicting write request */
56 P_PROTOCOL_UPDATE = 0x2d, /* data sock: is used in established connections */
57 /* 0x2e to 0x30 reserved, used in drbd 9 */
59 /* REQ_DISCARD. We used "discard" in different contexts before,
60 * which is why I chose TRIM here, to disambiguate. */
63 /* Only use these two if both support FF_THIN_RESYNC */
64 P_RS_THIN_REQ = 0x32, /* Request a block for resync or reply P_RS_DEALLOCATED */
65 P_RS_DEALLOCATED = 0x33, /* Contains only zeros on sync source node */
67 P_MAY_IGNORE = 0x100, /* Flag to test if (cmd > P_MAY_IGNORE) ... */
68 P_MAX_OPT_CMD = 0x101,
70 /* special command ids for handshake */
72 P_INITIAL_META = 0xfff1, /* First Packet on the MetaSock */
73 P_INITIAL_DATA = 0xfff2, /* First Packet on the Socket */
75 P_CONNECTION_FEATURES = 0xfffe /* FIXED for the next century! */
79 #define __packed __attribute__((packed))
82 /* This is the layout for a packet on the wire.
83 * The byteorder is the network byte order.
84 * (except block_id and barrier fields.
85 * these are pointers to local structs
86 * and have no relevance for the partner,
87 * which just echoes them as received.)
89 * NOTE that the payload starts at a long aligned offset,
90 * regardless of 32 or 64 bit arch!
95 u16 length; /* bytes of data after this header */
98 /* Header for big packets, Used for data packets exceeding 64kB */
100 u16 magic; /* use DRBD_MAGIC_BIG here */
113 /* these defines must not be changed without changing the protocol version */
114 #define DP_HARDBARRIER 1 /* depricated */
115 #define DP_RW_SYNC 2 /* equals REQ_SYNC */
116 #define DP_MAY_SET_IN_SYNC 4
117 #define DP_UNPLUG 8 /* not used anymore */
118 #define DP_FUA 16 /* equals REQ_FUA */
119 #define DP_FLUSH 32 /* equals REQ_PREFLUSH */
120 #define DP_DISCARD 64 /* equals REQ_DISCARD */
121 #define DP_SEND_RECEIVE_ACK 128 /* This is a proto B write request */
122 #define DP_SEND_WRITE_ACK 256 /* This is a proto C write request */
125 u64 sector; /* 64 bits sector number */
126 u64 block_id; /* to identify the request in protocol B&C */
132 struct p_data p_data;
133 u32 size; /* == bio->bi_size */
137 * commands which share a struct:
139 * P_RECV_ACK (proto B), P_WRITE_ACK (proto C),
140 * P_SUPERSEDED (proto C, two-primaries conflict detection)
142 * P_DATA_REQUEST, P_RS_DATA_REQUEST
155 u32 pad; /* to multiple of 8 Byte */
159 * commands with their own struct for additional fields:
160 * P_CONNECTION_FEATURES
168 #define FF_THIN_RESYNC 2
170 struct p_connection_features {
175 /* should be more than enough for future enhancements
176 * for now, feature_flags and the reserved array shall be zero.
184 u32 barrier; /* barrier number _handle_ only */
185 u32 pad; /* to multiple of 8 Byte */
188 struct p_barrier_ack {
196 /* Since protocol version 88 and higher. */
200 struct p_rs_param_89 {
202 /* protocol version 89: */
203 char verify_alg[SHARED_SECRET_MAX];
204 char csums_alg[SHARED_SECRET_MAX];
207 struct p_rs_param_95 {
209 char verify_alg[SHARED_SECRET_MAX];
210 char csums_alg[SHARED_SECRET_MAX];
217 enum drbd_conn_flags {
218 CF_DISCARD_MY_DATA = 1,
230 /* Since protocol version 87 and higher. */
231 char integrity_alg[0];
236 u64 uuid[UI_EXTENDED_SIZE];
244 u64 d_size; /* size of disk */
245 u64 u_size; /* user requested size */
246 u64 c_size; /* current exported size */
247 u32 max_bio_size; /* Maximal size of a BIO */
248 u16 queue_order_type; /* not yet implemented in DRBD*/
249 u16 dds_flags; /* use enum dds_flags here. */
261 struct p_req_state_reply {
265 struct p_drbd06_param {
275 struct p_block_desc {
278 u32 pad; /* to multiple of 8 Byte */
281 /* Valid values for the encoding field.
282 * Bump proto version when changing this. */
283 enum drbd_bitmap_code {
284 /* RLE_VLI_Bytes = 0,
285 * and other bit variants had been defined during
286 * algorithm evaluation. */
290 struct p_compressed_bm {
291 /* (encoding & 0x0f): actual encoding, see enum drbd_bitmap_code
292 * (encoding & 0x80): polarity (set/unset) of first runlength
293 * ((encoding >> 4) & 0x07): pad_bits, number of trailing zero bits
294 * used to pad up to head.length bytes
301 struct p_delay_probe93 {
302 u32 seq_num; /* sequence number to match the two probe packets */
303 u32 offset; /* usecs the probe got sent after the reference time point */
307 * Bitmap packets need to fit within a single page on the sender and receiver,
308 * so we are limited to 4 KiB (and not to PAGE_SIZE, which can be bigger).
310 #define DRBD_SOCKET_BUFFER_SIZE 4096
312 #endif /* __DRBD_PROTOCOL_H */