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