drivers/scsi/iscsi_tcp.h

   1 /*
   2  * iSCSI Initiator TCP Transport
   3  * Copyright (C) 2004 Dmitry Yusupov
   4  * Copyright (C) 2004 Alex Aizman
   5  * Copyright (C) 2005 Mike Christie
   6  * maintained by open-iscsi@googlegroups.com
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License as published
  10  * by the Free Software Foundation; either version 2 of the License, or
  11  * (at your option) any later version.
  12  *
  13  * This program is distributed in the hope that it will be useful, but
  14  * WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  16  * General Public License for more details.
  17  *
  18  * See the file COPYING included with this distribution for more details.
  19  */
  20
  21 #ifndef ISCSI_TCP_H
  22 #define ISCSI_TCP_H
  23
  24 /* Session's states */
  25 #define ISCSI_STATE_FREE                1
  26 #define ISCSI_STATE_LOGGED_IN           2
  27 #define ISCSI_STATE_FAILED              3
  28 #define ISCSI_STATE_TERMINATE           4
  29
  30 /* Connection's states */
  31 #define ISCSI_CONN_INITIAL_STAGE        0
  32 #define ISCSI_CONN_STARTED              1
  33 #define ISCSI_CONN_STOPPED              2
  34 #define ISCSI_CONN_CLEANUP_WAIT         3
  35
  36 /* Connection suspend "bit" */
  37 #define SUSPEND_BIT                     1
  38
  39 /* Socket's Receive state machine */
  40 #define IN_PROGRESS_WAIT_HEADER         0x0
  41 #define IN_PROGRESS_HEADER_GATHER       0x1
  42 #define IN_PROGRESS_DATA_RECV           0x2
  43 #define IN_PROGRESS_DDIGEST_RECV        0x3
  44
  45 /* Task Mgmt states */
  46 #define TMABORT_INITIAL                 0x0
  47 #define TMABORT_SUCCESS                 0x1
  48 #define TMABORT_FAILED                  0x2
  49 #define TMABORT_TIMEDOUT                0x3
  50
  51 /* xmit state machine */
  52 #define XMSTATE_IDLE                    0x0
  53 #define XMSTATE_R_HDR                   0x1
  54 #define XMSTATE_W_HDR                   0x2
  55 #define XMSTATE_IMM_HDR                 0x4
  56 #define XMSTATE_IMM_DATA                0x8
  57 #define XMSTATE_UNS_INIT                0x10
  58 #define XMSTATE_UNS_HDR                 0x20
  59 #define XMSTATE_UNS_DATA                0x40
  60 #define XMSTATE_SOL_HDR                 0x80
  61 #define XMSTATE_SOL_DATA                0x100
  62 #define XMSTATE_W_PAD                   0x200
  63 #define XMSTATE_DATA_DIGEST             0x400
  64
  65 #define ISCSI_CONN_MAX                  1
  66 #define ISCSI_CONN_RCVBUF_MIN           262144
  67 #define ISCSI_CONN_SNDBUF_MIN           262144
  68 #define ISCSI_PAD_LEN                   4
  69 #define ISCSI_R2T_MAX                   16
  70 #define ISCSI_XMIT_CMDS_MAX             128     /* must be power of 2 */
  71 #define ISCSI_MGMT_CMDS_MAX             32      /* must be power of 2 */
  72 #define ISCSI_MGMT_ITT_OFFSET           0xa00
  73 #define ISCSI_SG_TABLESIZE              SG_ALL
  74 #define ISCSI_DEF_CMD_PER_LUN           32
  75 #define ISCSI_MAX_CMD_PER_LUN           128
  76 #define ISCSI_TCP_MAX_CMD_LEN           16
  77
  78 #define ITT_MASK                        (0xfff)
  79 #define CID_SHIFT                       12
  80 #define CID_MASK                        (0xffff<<CID_SHIFT)
  81 #define AGE_SHIFT                       28
  82 #define AGE_MASK                        (0xf<<AGE_SHIFT)
  83
  84 struct iscsi_queue {
  85         struct kfifo            *queue;         /* FIFO Queue */
  86         void                    **pool;         /* Pool of elements */
  87         int                     max;            /* Max number of elements */
  88 };
  89
  90 struct iscsi_session;
  91 struct iscsi_cmd_task;
  92 struct iscsi_mgmt_task;
  93
  94 /* Socket connection recieve helper */
  95 struct iscsi_tcp_recv {
  96         struct iscsi_hdr        *hdr;
  97         struct sk_buff          *skb;
  98         int                     offset;
  99         int                     len;
 100         int                     hdr_offset;
 101         int                     copy;
 102         int                     copied;
 103         int                     padding;
 104         struct iscsi_cmd_task   *ctask;         /* current cmd in progress */
 105
 106         /* copied and flipped values */
 107         int                     opcode;
 108         int                     flags;
 109         int                     cmd_status;
 110         int                     ahslen;
 111         int                     datalen;
 112         uint32_t                itt;
 113         int                     datadgst;
 114 };
 115
 116 struct iscsi_conn {
 117         struct iscsi_hdr        hdr;            /* header placeholder */
 118         char                    hdrext[4*sizeof(__u16) +
 119                                     sizeof(__u32)];
 120         int                     data_copied;
 121         char                    *data;          /* data placeholder */
 122         struct socket           *sock;          /* TCP socket */
 123         int                     data_size;      /* actual recv_dlength */
 124         int                     stop_stage;     /* conn_stop() flag: *
 125                                                  * stop to recover,  *
 126                                                  * stop to terminate */
 127         /* iSCSI connection-wide sequencing */
 128         uint32_t                exp_statsn;
 129         int                     hdr_size;       /* PDU header size */
 130         unsigned long           suspend_rx;     /* suspend Rx */
 131
 132         struct crypto_tfm       *rx_tfm;        /* CRC32C (Rx) */
 133         struct crypto_tfm       *data_rx_tfm;   /* CRC32C (Rx) for data */
 134
 135         /* control data */
 136         int                     senselen;       /* scsi sense length */
 137         int                     id;             /* CID */
 138         struct iscsi_tcp_recv   in;             /* TCP receive context */
 139         struct iscsi_session    *session;       /* parent session */
 140         struct list_head        item;           /* maintains list of conns */
 141         int                     in_progress;    /* connection state machine */
 142         int                     c_stage;        /* connection state */
 143         struct iscsi_mgmt_task  *login_mtask;   /* mtask used for login/text */
 144         struct iscsi_mgmt_task  *mtask;         /* xmit mtask in progress */
 145         struct iscsi_cmd_task   *ctask;         /* xmit ctask in progress */
 146         spinlock_t              lock;           /* FIXME: to be removed */
 147
 148         /* old values for socket callbacks */
 149         void                    (*old_data_ready)(struct sock *, int);
 150         void                    (*old_state_change)(struct sock *);
 151         void                    (*old_write_space)(struct sock *);
 152
 153         /* xmit */
 154         struct crypto_tfm       *tx_tfm;        /* CRC32C (Tx) */
 155         struct crypto_tfm       *data_tx_tfm;   /* CRC32C (Tx) for data */
 156         struct kfifo            *writequeue;    /* write cmds for Data-Outs */
 157         struct kfifo            *immqueue;      /* immediate xmit queue */
 158         struct kfifo            *mgmtqueue;     /* mgmt (control) xmit queue */
 159         struct kfifo            *xmitqueue;     /* data-path cmd queue */
 160         struct work_struct      xmitwork;       /* per-conn. xmit workqueue */
 161         struct mutex            xmitmutex;      /* serializes connection xmit,
 162                                                  * access to kfifos:      *
 163                                                  * xmitqueue, writequeue, *
 164                                                  * immqueue, mgmtqueue    */
 165         unsigned long           suspend_tx;     /* suspend Tx */
 166
 167         /* abort */
 168         wait_queue_head_t       ehwait;         /* used in eh_abort()     */
 169         struct iscsi_tm         tmhdr;
 170         struct timer_list       tmabort_timer;  /* abort timer */
 171         int                     tmabort_state;  /* see TMABORT_INITIAL, etc.*/
 172
 173         /* negotiated params */
 174         int                     max_recv_dlength;
 175         int                     max_xmit_dlength;
 176         int                     hdrdgst_en;
 177         int                     datadgst_en;
 178
 179         /* MIB-statistics */
 180         uint64_t                txdata_octets;
 181         uint64_t                rxdata_octets;
 182         uint32_t                scsicmd_pdus_cnt;
 183         uint32_t                dataout_pdus_cnt;
 184         uint32_t                scsirsp_pdus_cnt;
 185         uint32_t                datain_pdus_cnt;
 186         uint32_t                r2t_pdus_cnt;
 187         uint32_t                tmfcmd_pdus_cnt;
 188         int32_t                 tmfrsp_pdus_cnt;
 189
 190         /* custom statistics */
 191         uint32_t                sendpage_failures_cnt;
 192         uint32_t                discontiguous_hdr_cnt;
 193         uint32_t                eh_abort_cnt;
 194
 195         ssize_t (*sendpage)(struct socket *, struct page *, int, size_t, int);
 196 };
 197
 198 struct iscsi_session {
 199         /* iSCSI session-wide sequencing */
 200         uint32_t                cmdsn;
 201         uint32_t                exp_cmdsn;
 202         uint32_t                max_cmdsn;
 203
 204         /* configuration */
 205         int                     initial_r2t_en;
 206         int                     max_r2t;
 207         int                     imm_data_en;
 208         int                     first_burst;
 209         int                     max_burst;
 210         int                     time2wait;
 211         int                     time2retain;
 212         int                     pdu_inorder_en;
 213         int                     dataseq_inorder_en;
 214         int                     erl;
 215         int                     ifmarker_en;
 216         int                     ofmarker_en;
 217
 218         /* control data */
 219         struct Scsi_Host        *host;
 220         int                     id;
 221         struct iscsi_conn       *leadconn;      /* leading connection */
 222         spinlock_t              lock;           /* protects session state, *
 223                                                  * sequence numbers,       *
 224                                                  * session resources:      *
 225                                                  * - cmdpool,              *
 226                                                  * - mgmtpool,             *
 227                                                  * - r2tpool               */
 228         int                     state;          /* session state           */
 229         struct list_head        item;
 230         void                    *auth_client;
 231         int                     conn_cnt;
 232         int                     age;            /* counts session re-opens */
 233
 234         struct list_head        connections;    /* list of connections */
 235         int                     cmds_max;       /* size of cmds array */
 236         struct iscsi_cmd_task   **cmds;         /* Original Cmds arr */
 237         struct iscsi_queue      cmdpool;        /* PDU's pool */
 238         int                     mgmtpool_max;   /* size of mgmt array */
 239         struct iscsi_mgmt_task  **mgmt_cmds;    /* Original mgmt arr */
 240         struct iscsi_queue      mgmtpool;       /* Mgmt PDU's pool */
 241 };
 242
 243 struct iscsi_buf {
 244         struct scatterlist      sg;
 245         unsigned int            sent;
 246         char                    use_sendmsg;
 247 };
 248
 249 struct iscsi_data_task {
 250         struct iscsi_data       hdr;                    /* PDU */
 251         char                    hdrext[sizeof(__u32)];  /* Header-Digest */
 252         struct list_head        item;                   /* data queue item */
 253         struct iscsi_buf        digestbuf;              /* digest buffer */
 254         uint32_t                digest;                 /* data digest */
 255 };
 256 #define ISCSI_DTASK_DEFAULT_MAX ISCSI_SG_TABLESIZE * PAGE_SIZE / 512
 257
 258 struct iscsi_mgmt_task {
 259         struct iscsi_hdr        hdr;            /* mgmt. PDU */
 260         char                    hdrext[sizeof(__u32)];  /* Header-Digest */
 261         char                    *data;          /* mgmt payload */
 262         int                     xmstate;        /* mgmt xmit progress */
 263         int                     data_count;     /* counts data to be sent */
 264         struct iscsi_buf        headbuf;        /* header buffer */
 265         struct iscsi_buf        sendbuf;        /* in progress buffer */
 266         int                     sent;
 267         uint32_t                itt;            /* this ITT */
 268 };
 269
 270 struct iscsi_r2t_info {
 271         __be32                  ttt;            /* copied from R2T */
 272         __be32                  exp_statsn;     /* copied from R2T */
 273         uint32_t                data_length;    /* copied from R2T */
 274         uint32_t                data_offset;    /* copied from R2T */
 275         struct iscsi_buf        headbuf;        /* Data-Out Header Buffer */
 276         struct iscsi_buf        sendbuf;        /* Data-Out in progress buffer*/
 277         int                     sent;           /* R2T sequence progress */
 278         int                     data_count;     /* DATA-Out payload progress */
 279         struct scatterlist      *sg;            /* per-R2T SG list */
 280         int                     solicit_datasn;
 281         struct iscsi_data_task   *dtask;        /* which data task */
 282 };
 283
 284 struct iscsi_cmd_task {
 285         struct iscsi_cmd        hdr;                    /* iSCSI PDU header */
 286         char                    hdrext[4*sizeof(__u16)+ /* AHS */
 287                                     sizeof(__u32)];     /* HeaderDigest */
 288         char                    pad[ISCSI_PAD_LEN];
 289         int                     itt;                    /* this ITT */
 290         int                     datasn;                 /* DataSN */
 291         struct iscsi_buf        headbuf;                /* header buf (xmit) */
 292         struct iscsi_buf        sendbuf;                /* in progress buffer*/
 293         int                     sent;
 294         struct scatterlist      *sg;                    /* per-cmd SG list  */
 295         struct scatterlist      *bad_sg;                /* assert statement */
 296         int                     sg_count;               /* SG's to process  */
 297         uint32_t                unsol_datasn;
 298         uint32_t                exp_r2tsn;
 299         int                     xmstate;                /* xmit xtate machine */
 300         int                     imm_count;              /* imm-data (bytes)   */
 301         int                     unsol_count;            /* unsolicited (bytes)*/
 302         int                     r2t_data_count;         /* R2T Data-Out bytes */
 303         int                     data_count;             /* remaining Data-Out */
 304         int                     pad_count;              /* padded bytes */
 305         struct scsi_cmnd        *sc;                    /* associated SCSI cmd*/
 306         int                     total_length;
 307         int                     data_offset;
 308         struct iscsi_conn       *conn;                  /* used connection    */
 309         struct iscsi_mgmt_task  *mtask;                 /* tmf mtask in progr */
 310
 311         struct iscsi_r2t_info   *r2t;                   /* in progress R2T    */
 312         struct iscsi_queue      r2tpool;
 313         struct kfifo            *r2tqueue;
 314         struct iscsi_r2t_info   **r2ts;
 315         struct list_head        dataqueue;              /* Data-Out dataqueue */
 316         mempool_t               *datapool;
 317         uint32_t                datadigest;             /* for recover digest */
 318         int                     digest_count;
 319         uint32_t                immdigest;              /* for imm data */
 320         struct iscsi_buf        immbuf;                 /* for imm data digest */
 321         struct iscsi_data_task   *dtask;                /* data task in progress*/
 322         int                     digest_offset;          /* for partial buff digest */
 323 };
 324
 325 #endif /* ISCSI_H */