[linux-2.6-block.git] / drivers / block / drbd / drbd_protocol.h

#ifndef __DRBD_PROTOCOL_H
#define __DRBD_PROTOCOL_H

enum drbd_packet {
	/* receiver (data socket) */
	P_DATA		      = 0x00,
	P_DATA_REPLY	      = 0x01, /* Response to P_DATA_REQUEST */
	P_RS_DATA_REPLY	      = 0x02, /* Response to P_RS_DATA_REQUEST */
	P_BARRIER	      = 0x03,
	P_BITMAP	      = 0x04,
	P_BECOME_SYNC_TARGET  = 0x05,
	P_BECOME_SYNC_SOURCE  = 0x06,
	P_UNPLUG_REMOTE	      = 0x07, /* Used at various times to hint the peer */
	P_DATA_REQUEST	      = 0x08, /* Used to ask for a data block */
	P_RS_DATA_REQUEST     = 0x09, /* Used to ask for a data block for resync */
	P_SYNC_PARAM	      = 0x0a,
	P_PROTOCOL	      = 0x0b,
	P_UUIDS		      = 0x0c,
	P_SIZES		      = 0x0d,
	P_STATE		      = 0x0e,
	P_SYNC_UUID	      = 0x0f,
	P_AUTH_CHALLENGE      = 0x10,
	P_AUTH_RESPONSE	      = 0x11,
	P_STATE_CHG_REQ	      = 0x12,

	/* asender (meta socket */
	P_PING		      = 0x13,
	P_PING_ACK	      = 0x14,
	P_RECV_ACK	      = 0x15, /* Used in protocol B */
	P_WRITE_ACK	      = 0x16, /* Used in protocol C */
	P_RS_WRITE_ACK	      = 0x17, /* Is a P_WRITE_ACK, additionally call set_in_sync(). */
	P_SUPERSEDED	      = 0x18, /* Used in proto C, two-primaries conflict detection */
	P_NEG_ACK	      = 0x19, /* Sent if local disk is unusable */
	P_NEG_DREPLY	      = 0x1a, /* Local disk is broken... */
	P_NEG_RS_DREPLY	      = 0x1b, /* Local disk is broken... */
	P_BARRIER_ACK	      = 0x1c,
	P_STATE_CHG_REPLY     = 0x1d,

	/* "new" commands, no longer fitting into the ordering scheme above */

	P_OV_REQUEST	      = 0x1e, /* data socket */
	P_OV_REPLY	      = 0x1f,
	P_OV_RESULT	      = 0x20, /* meta socket */
	P_CSUM_RS_REQUEST     = 0x21, /* data socket */
	P_RS_IS_IN_SYNC	      = 0x22, /* meta socket */
	P_SYNC_PARAM89	      = 0x23, /* data socket, protocol version 89 replacement for P_SYNC_PARAM */
	P_COMPRESSED_BITMAP   = 0x24, /* compressed or otherwise encoded bitmap transfer */
	/* P_CKPT_FENCE_REQ      = 0x25, * currently reserved for protocol D */
	/* P_CKPT_DISABLE_REQ    = 0x26, * currently reserved for protocol D */
	P_DELAY_PROBE         = 0x27, /* is used on BOTH sockets */
	P_OUT_OF_SYNC         = 0x28, /* Mark as out of sync (Outrunning), data socket */
	P_RS_CANCEL           = 0x29, /* meta: Used to cancel RS_DATA_REQUEST packet by SyncSource */
	P_CONN_ST_CHG_REQ     = 0x2a, /* data sock: Connection wide state request */
	P_CONN_ST_CHG_REPLY   = 0x2b, /* meta sock: Connection side state req reply */
	P_RETRY_WRITE	      = 0x2c, /* Protocol C: retry conflicting write request */
	P_PROTOCOL_UPDATE     = 0x2d, /* data sock: is used in established connections */
        /* 0x2e to 0x30 reserved, used in drbd 9 */

	/* REQ_DISCARD. We used "discard" in different contexts before,
	 * which is why I chose TRIM here, to disambiguate. */
	P_TRIM                = 0x31,

	P_MAY_IGNORE	      = 0x100, /* Flag to test if (cmd > P_MAY_IGNORE) ... */
	P_MAX_OPT_CMD	      = 0x101,

	/* special command ids for handshake */

	P_INITIAL_META	      = 0xfff1, /* First Packet on the MetaSock */
	P_INITIAL_DATA	      = 0xfff2, /* First Packet on the Socket */

	P_CONNECTION_FEATURES = 0xfffe	/* FIXED for the next century! */
};

#ifndef __packed
#define __packed __attribute__((packed))
#endif

/* This is the layout for a packet on the wire.
 * The byteorder is the network byte order.
 *     (except block_id and barrier fields.
 *	these are pointers to local structs
 *	and have no relevance for the partner,
 *	which just echoes them as received.)
 *
 * NOTE that the payload starts at a long aligned offset,
 * regardless of 32 or 64 bit arch!
 */
struct p_header80 {
	u32	  magic;
	u16	  command;
	u16	  length;	/* bytes of data after this header */
} __packed;

/* Header for big packets, Used for data packets exceeding 64kB */
struct p_header95 {
	u16	  magic;	/* use DRBD_MAGIC_BIG here */
	u16	  command;
	u32	  length;
} __packed;

struct p_header100 {
	u32	  magic;
	u16	  volume;
	u16	  command;
	u32	  length;
	u32	  pad;
} __packed;

/* these defines must not be changed without changing the protocol version */
#define DP_HARDBARRIER	      1 /* depricated */
#define DP_RW_SYNC	      2 /* equals REQ_SYNC    */
#define DP_MAY_SET_IN_SYNC    4
#define DP_UNPLUG             8 /* not used anymore   */
#define DP_FUA               16 /* equals REQ_FUA     */
#define DP_FLUSH             32 /* equals REQ_FLUSH   */
#define DP_DISCARD           64 /* equals REQ_DISCARD */
#define DP_SEND_RECEIVE_ACK 128 /* This is a proto B write request */
#define DP_SEND_WRITE_ACK   256 /* This is a proto C write request */

struct p_data {
	u64	    sector;    /* 64 bits sector number */
	u64	    block_id;  /* to identify the request in protocol B&C */
	u32	    seq_num;
	u32	    dp_flags;
} __packed;

struct p_trim {
	struct p_data p_data;
	u32	    size;	/* == bio->bi_size */
} __packed;

/*
 * commands which share a struct:
 *  p_block_ack:
 *   P_RECV_ACK (proto B), P_WRITE_ACK (proto C),
 *   P_SUPERSEDED (proto C, two-primaries conflict detection)
 *  p_block_req:
 *   P_DATA_REQUEST, P_RS_DATA_REQUEST
 */
struct p_block_ack {
	u64	    sector;
	u64	    block_id;
	u32	    blksize;
	u32	    seq_num;
} __packed;

struct p_block_req {
	u64 sector;
	u64 block_id;
	u32 blksize;
	u32 pad;	/* to multiple of 8 Byte */
} __packed;

/*
 * commands with their own struct for additional fields:
 *   P_CONNECTION_FEATURES
 *   P_BARRIER
 *   P_BARRIER_ACK
 *   P_SYNC_PARAM
 *   ReportParams
 */

struct p_connection_features {
	u32 protocol_min;
	u32 feature_flags;
	u32 protocol_max;

	/* should be more than enough for future enhancements
	 * for now, feature_flags and the reserved array shall be zero.
	 */

	u32 _pad;
	u64 reserved[7];
} __packed;

struct p_barrier {
	u32 barrier;	/* barrier number _handle_ only */
	u32 pad;	/* to multiple of 8 Byte */
} __packed;

struct p_barrier_ack {
	u32 barrier;
	u32 set_size;
} __packed;

struct p_rs_param {
	u32 resync_rate;

	      /* Since protocol version 88 and higher. */
	char verify_alg[0];
} __packed;

struct p_rs_param_89 {
	u32 resync_rate;
	/* protocol version 89: */
	char verify_alg[SHARED_SECRET_MAX];
	char csums_alg[SHARED_SECRET_MAX];
} __packed;

struct p_rs_param_95 {
	u32 resync_rate;
	char verify_alg[SHARED_SECRET_MAX];
	char csums_alg[SHARED_SECRET_MAX];
	u32 c_plan_ahead;
	u32 c_delay_target;
	u32 c_fill_target;
	u32 c_max_rate;
} __packed;

enum drbd_conn_flags {
	CF_DISCARD_MY_DATA = 1,
	CF_DRY_RUN = 2,
};

struct p_protocol {
	u32 protocol;
	u32 after_sb_0p;
	u32 after_sb_1p;
	u32 after_sb_2p;
	u32 conn_flags;
	u32 two_primaries;

	/* Since protocol version 87 and higher. */
	char integrity_alg[0];

} __packed;

struct p_uuids {
	u64 uuid[UI_EXTENDED_SIZE];
} __packed;

struct p_rs_uuid {
	u64	    uuid;
} __packed;

struct p_sizes {
	u64	    d_size;  /* size of disk */
	u64	    u_size;  /* user requested size */
	u64	    c_size;  /* current exported size */
	u32	    max_bio_size;  /* Maximal size of a BIO */
	u16	    queue_order_type;  /* not yet implemented in DRBD*/
	u16	    dds_flags; /* use enum dds_flags here. */
} __packed;

struct p_state {
	u32	    state;
} __packed;

struct p_req_state {
	u32	    mask;
	u32	    val;
} __packed;

struct p_req_state_reply {
	u32	    retcode;
} __packed;

struct p_drbd06_param {
	u64	  size;
	u32	  state;
	u32	  blksize;
	u32	  protocol;
	u32	  version;
	u32	  gen_cnt[5];
	u32	  bit_map_gen[5];
} __packed;

struct p_block_desc {
	u64 sector;
	u32 blksize;
	u32 pad;	/* to multiple of 8 Byte */
} __packed;

/* Valid values for the encoding field.
 * Bump proto version when changing this. */
enum drbd_bitmap_code {
	/* RLE_VLI_Bytes = 0,
	 * and other bit variants had been defined during
	 * algorithm evaluation. */
	RLE_VLI_Bits = 2,
};

struct p_compressed_bm {
	/* (encoding & 0x0f): actual encoding, see enum drbd_bitmap_code
	 * (encoding & 0x80): polarity (set/unset) of first runlength
	 * ((encoding >> 4) & 0x07): pad_bits, number of trailing zero bits
	 * used to pad up to head.length bytes
	 */
	u8 encoding;

	u8 code[0];
} __packed;

struct p_delay_probe93 {
	u32     seq_num; /* sequence number to match the two probe packets */
	u32     offset;  /* usecs the probe got sent after the reference time point */
} __packed;

/*
 * Bitmap packets need to fit within a single page on the sender and receiver,
 * so we are limited to 4 KiB (and not to PAGE_SIZE, which can be bigger).
 */
#define DRBD_SOCKET_BUFFER_SIZE 4096

#endif  /* __DRBD_PROTOCOL_H */
Commit	Line	Data
a3603a6e AG	1	#ifndef __DRBD_PROTOCOL_H
	2	#define __DRBD_PROTOCOL_H
	3
	4	enum drbd_packet {
	5	/* receiver (data socket) */
	6	P_DATA = 0x00,
	7	P_DATA_REPLY = 0x01, /* Response to P_DATA_REQUEST */
	8	P_RS_DATA_REPLY = 0x02, /* Response to P_RS_DATA_REQUEST */
	9	P_BARRIER = 0x03,
	10	P_BITMAP = 0x04,
	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 */
	16	P_SYNC_PARAM = 0x0a,
	17	P_PROTOCOL = 0x0b,
	18	P_UUIDS = 0x0c,
	19	P_SIZES = 0x0d,
	20	P_STATE = 0x0e,
	21	P_SYNC_UUID = 0x0f,
	22	P_AUTH_CHALLENGE = 0x10,
	23	P_AUTH_RESPONSE = 0x11,
	24	P_STATE_CHG_REQ = 0x12,
	25
	26	/* asender (meta socket */
	27	P_PING = 0x13,
	28	P_PING_ACK = 0x14,
	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... */
	36	P_BARRIER_ACK = 0x1c,
	37	P_STATE_CHG_REPLY = 0x1d,
	38
	39	/* "new" commands, no longer fitting into the ordering scheme above */
	40
	41	P_OV_REQUEST = 0x1e, /* data socket */
	42	P_OV_REPLY = 0x1f,
	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 */
a0fb3c47 LE	57	/* 0x2e to 0x30 reserved, used in drbd 9 */
	58
	59	/* REQ_DISCARD. We used "discard" in different contexts before,
	60	* which is why I chose TRIM here, to disambiguate. */
	61	P_TRIM = 0x31,
a3603a6e AG	62
	63	P_MAY_IGNORE = 0x100, /* Flag to test if (cmd > P_MAY_IGNORE) ... */
	64	P_MAX_OPT_CMD = 0x101,
	65
	66	/* special command ids for handshake */
	67
	68	P_INITIAL_META = 0xfff1, /* First Packet on the MetaSock */
	69	P_INITIAL_DATA = 0xfff2, /* First Packet on the Socket */
	70
	71	P_CONNECTION_FEATURES = 0xfffe /* FIXED for the next century! */
	72	};
	73
	74	#ifndef __packed
	75	#define __packed __attribute__((packed))
	76	#endif
	77
	78	/* This is the layout for a packet on the wire.
	79	* The byteorder is the network byte order.
	80	* (except block_id and barrier fields.
	81	* these are pointers to local structs
	82	* and have no relevance for the partner,
	83	* which just echoes them as received.)
	84	*
	85	* NOTE that the payload starts at a long aligned offset,
	86	* regardless of 32 or 64 bit arch!
	87	*/
	88	struct p_header80 {
	89	u32 magic;
	90	u16 command;
	91	u16 length; /* bytes of data after this header */
	92	} __packed;
	93
	94	/* Header for big packets, Used for data packets exceeding 64kB */
	95	struct p_header95 {
	96	u16 magic; /* use DRBD_MAGIC_BIG here */
	97	u16 command;
	98	u32 length;
	99	} __packed;
	100
	101	struct p_header100 {
	102	u32 magic;
	103	u16 volume;
	104	u16 command;
	105	u32 length;
	106	u32 pad;
	107	} __packed;
	108
	109	/* these defines must not be changed without changing the protocol version */
	110	#define DP_HARDBARRIER 1 /* depricated */
	111	#define DP_RW_SYNC 2 /* equals REQ_SYNC */
	112	#define DP_MAY_SET_IN_SYNC 4
	113	#define DP_UNPLUG 8 /* not used anymore */
	114	#define DP_FUA 16 /* equals REQ_FUA */
	115	#define DP_FLUSH 32 /* equals REQ_FLUSH */
	116	#define DP_DISCARD 64 /* equals REQ_DISCARD */
	117	#define DP_SEND_RECEIVE_ACK 128 /* This is a proto B write request */
	118	#define DP_SEND_WRITE_ACK 256 /* This is a proto C write request */
	119
	120	struct p_data {
	121	u64 sector; /* 64 bits sector number */
	122	u64 block_id; /* to identify the request in protocol B&C */
	123	u32 seq_num;
	124	u32 dp_flags;
	125	} __packed;
126
a0fb3c47 LE	127	struct p_trim {
	128	struct p_data p_data;
	129	u32 size; /* == bio->bi_size */
	130	} __packed;
	131
a3603a6e AG	132	/*
	133	* commands which share a struct:
	134	* p_block_ack:
	135	* P_RECV_ACK (proto B), P_WRITE_ACK (proto C),
	136	* P_SUPERSEDED (proto C, two-primaries conflict detection)
	137	* p_block_req:
	138	* P_DATA_REQUEST, P_RS_DATA_REQUEST
	139	*/
	140	struct p_block_ack {
	141	u64 sector;
	142	u64 block_id;
	143	u32 blksize;
	144	u32 seq_num;
	145	} __packed;
	146
	147	struct p_block_req {
	148	u64 sector;
	149	u64 block_id;
	150	u32 blksize;
	151	u32 pad; /* to multiple of 8 Byte */
	152	} __packed;
	153
	154	/*
	155	* commands with their own struct for additional fields:
	156	* P_CONNECTION_FEATURES
	157	* P_BARRIER
	158	* P_BARRIER_ACK
	159	* P_SYNC_PARAM
	160	* ReportParams
	161	*/
	162
	163	struct p_connection_features {
	164	u32 protocol_min;
	165	u32 feature_flags;
	166	u32 protocol_max;
	167
	168	/* should be more than enough for future enhancements
	169	* for now, feature_flags and the reserved array shall be zero.
	170	*/
	171
	172	u32 _pad;
	173	u64 reserved[7];
	174	} __packed;
	175
	176	struct p_barrier {
	177	u32 barrier; /* barrier number _handle_ only */
	178	u32 pad; /* to multiple of 8 Byte */
	179	} __packed;
	180
	181	struct p_barrier_ack {
	182	u32 barrier;
	183	u32 set_size;
	184	} __packed;
	185
	186	struct p_rs_param {
	187	u32 resync_rate;
	188
	189	/* Since protocol version 88 and higher. */
	190	char verify_alg[0];
	191	} __packed;
	192
	193	struct p_rs_param_89 {
	194	u32 resync_rate;
	195	/* protocol version 89: */
196	char verify_alg[SHARED_SECRET_MAX];
197	char csums_alg[SHARED_SECRET_MAX];
198	} __packed;
199
200	struct p_rs_param_95 {
201	u32 resync_rate;
202	char verify_alg[SHARED_SECRET_MAX];
203	char csums_alg[SHARED_SECRET_MAX];
204	u32 c_plan_ahead;
205	u32 c_delay_target;
206	u32 c_fill_target;
207	u32 c_max_rate;
208	} __packed;
209
210	enum drbd_conn_flags {
211	CF_DISCARD_MY_DATA = 1,
212	CF_DRY_RUN = 2,
213	};
214
215	struct p_protocol {
216	u32 protocol;
217	u32 after_sb_0p;
218	u32 after_sb_1p;
219	u32 after_sb_2p;
220	u32 conn_flags;
221	u32 two_primaries;
222
223	/* Since protocol version 87 and higher. */
224	char integrity_alg[0];
225
226	} __packed;
227
228	struct p_uuids {
229	u64 uuid[UI_EXTENDED_SIZE];
230	} __packed;
231
232	struct p_rs_uuid {
233	u64 uuid;
234	} __packed;
235
236	struct p_sizes {
237	u64 d_size; /* size of disk */
238	u64 u_size; /* user requested size */
239	u64 c_size; /* current exported size */
240	u32 max_bio_size; /* Maximal size of a BIO */
241	u16 queue_order_type; /* not yet implemented in DRBD*/
242	u16 dds_flags; /* use enum dds_flags here. */
243	} __packed;
244
245	struct p_state {
246	u32 state;
247	} __packed;
248
249	struct p_req_state {
250	u32 mask;
251	u32 val;
252	} __packed;
253
254	struct p_req_state_reply {
255	u32 retcode;
256	} __packed;
257
258	struct p_drbd06_param {
259	u64 size;
260	u32 state;
261	u32 blksize;
262	u32 protocol;
263	u32 version;
264	u32 gen_cnt[5];
265	u32 bit_map_gen[5];
266	} __packed;
267
268	struct p_block_desc {
269	u64 sector;
270	u32 blksize;
271	u32 pad; /* to multiple of 8 Byte */
272	} __packed;
273
274	/* Valid values for the encoding field.
275	* Bump proto version when changing this. */
276	enum drbd_bitmap_code {
277	/* RLE_VLI_Bytes = 0,
278	* and other bit variants had been defined during
279	* algorithm evaluation. */
280	RLE_VLI_Bits = 2,
281	};
282
283	struct p_compressed_bm {
284	/* (encoding & 0x0f): actual encoding, see enum drbd_bitmap_code
285	* (encoding & 0x80): polarity (set/unset) of first runlength
286	* ((encoding >> 4) & 0x07): pad_bits, number of trailing zero bits
287	* used to pad up to head.length bytes
288	*/
289	u8 encoding;
290
291	u8 code[0];
292	} __packed;
293
294	struct p_delay_probe93 {
295	u32 seq_num; /* sequence number to match the two probe packets */
296	u32 offset; /* usecs the probe got sent after the reference time point */
297	} __packed;
298
299	/*
300	* Bitmap packets need to fit within a single page on the sender and receiver,
301	* so we are limited to 4 KiB (and not to PAGE_SIZE, which can be bigger).
302	*/
303	#define DRBD_SOCKET_BUFFER_SIZE 4096
304
305	#endif /* __DRBD_PROTOCOL_H */