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 /* (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 /* 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, 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; 126 127 struct p_trim { 128 struct p_data p_data; 129 u32 size; /* == bio->bi_size */ 130 } __packed; 131 132 /* 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 #define FF_TRIM 1 164 165 struct p_connection_features { 166 u32 protocol_min; 167 u32 feature_flags; 168 u32 protocol_max; 169 170 /* should be more than enough for future enhancements 171 * for now, feature_flags and the reserved array shall be zero. 172 */ 173 174 u32 _pad; 175 u64 reserved[7]; 176 } __packed; 177 178 struct p_barrier { 179 u32 barrier; /* barrier number _handle_ only */ 180 u32 pad; /* to multiple of 8 Byte */ 181 } __packed; 182 183 struct p_barrier_ack { 184 u32 barrier; 185 u32 set_size; 186 } __packed; 187 188 struct p_rs_param { 189 u32 resync_rate; 190 191 /* Since protocol version 88 and higher. */ 192 char verify_alg[0]; 193 } __packed; 194 195 struct p_rs_param_89 { 196 u32 resync_rate; 197 /* protocol version 89: */ 198 char verify_alg[SHARED_SECRET_MAX]; 199 char csums_alg[SHARED_SECRET_MAX]; 200 } __packed; 201 202 struct p_rs_param_95 { 203 u32 resync_rate; 204 char verify_alg[SHARED_SECRET_MAX]; 205 char csums_alg[SHARED_SECRET_MAX]; 206 u32 c_plan_ahead; 207 u32 c_delay_target; 208 u32 c_fill_target; 209 u32 c_max_rate; 210 } __packed; 211 212 enum drbd_conn_flags { 213 CF_DISCARD_MY_DATA = 1, 214 CF_DRY_RUN = 2, 215 }; 216 217 struct p_protocol { 218 u32 protocol; 219 u32 after_sb_0p; 220 u32 after_sb_1p; 221 u32 after_sb_2p; 222 u32 conn_flags; 223 u32 two_primaries; 224 225 /* Since protocol version 87 and higher. */ 226 char integrity_alg[0]; 227 228 } __packed; 229 230 struct p_uuids { 231 u64 uuid[UI_EXTENDED_SIZE]; 232 } __packed; 233 234 struct p_rs_uuid { 235 u64 uuid; 236 } __packed; 237 238 struct p_sizes { 239 u64 d_size; /* size of disk */ 240 u64 u_size; /* user requested size */ 241 u64 c_size; /* current exported size */ 242 u32 max_bio_size; /* Maximal size of a BIO */ 243 u16 queue_order_type; /* not yet implemented in DRBD*/ 244 u16 dds_flags; /* use enum dds_flags here. */ 245 } __packed; 246 247 struct p_state { 248 u32 state; 249 } __packed; 250 251 struct p_req_state { 252 u32 mask; 253 u32 val; 254 } __packed; 255 256 struct p_req_state_reply { 257 u32 retcode; 258 } __packed; 259 260 struct p_drbd06_param { 261 u64 size; 262 u32 state; 263 u32 blksize; 264 u32 protocol; 265 u32 version; 266 u32 gen_cnt[5]; 267 u32 bit_map_gen[5]; 268 } __packed; 269 270 struct p_block_desc { 271 u64 sector; 272 u32 blksize; 273 u32 pad; /* to multiple of 8 Byte */ 274 } __packed; 275 276 /* Valid values for the encoding field. 277 * Bump proto version when changing this. */ 278 enum drbd_bitmap_code { 279 /* RLE_VLI_Bytes = 0, 280 * and other bit variants had been defined during 281 * algorithm evaluation. */ 282 RLE_VLI_Bits = 2, 283 }; 284 285 struct p_compressed_bm { 286 /* (encoding & 0x0f): actual encoding, see enum drbd_bitmap_code 287 * (encoding & 0x80): polarity (set/unset) of first runlength 288 * ((encoding >> 4) & 0x07): pad_bits, number of trailing zero bits 289 * used to pad up to head.length bytes 290 */ 291 u8 encoding; 292 293 u8 code[0]; 294 } __packed; 295 296 struct p_delay_probe93 { 297 u32 seq_num; /* sequence number to match the two probe packets */ 298 u32 offset; /* usecs the probe got sent after the reference time point */ 299 } __packed; 300 301 /* 302 * Bitmap packets need to fit within a single page on the sender and receiver, 303 * so we are limited to 4 KiB (and not to PAGE_SIZE, which can be bigger). 304 */ 305 #define DRBD_SOCKET_BUFFER_SIZE 4096 306 307 #endif /* __DRBD_PROTOCOL_H */ 308