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   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_CMD_PER_LUN               128
  75 #define ISCSI_TCP_MAX_CMD_LEN           16
  76
  77 #define ITT_MASK                        (0xfff)
  78 #define CID_SHIFT                       12
  79 #define CID_MASK                        (0xffff<<CID_SHIFT)
  80 #define AGE_SHIFT                       28
  81 #define AGE_MASK                        (0xf<<AGE_SHIFT)
  82
  83 struct iscsi_queue {
  84         struct kfifo            *queue;         /* FIFO Queue */
  85         void                    **pool;         /* Pool of elements */
  86         int                     max;            /* Max number of elements */
  87 };
  88
  89 struct iscsi_session;
  90 struct iscsi_cmd_task;
  91 struct iscsi_mgmt_task;
  92
  93 /* Socket connection recieve helper */
  94 struct iscsi_tcp_recv {
  95         struct iscsi_hdr        *hdr;
  96         struct sk_buff          *skb;
  97         int                     offset;
  98         int                     len;
  99         int                     hdr_offset;
 100         int                     copy;
 101         int                     copied;
 102         int                     padding;
 103         struct iscsi_cmd_task   *ctask;         /* current cmd in progress */
 104
 105         /* copied and flipped values */
 106         int                     opcode;
 107         int                     flags;
 108         int                     cmd_status;
 109         int                     ahslen;
 110         int                     datalen;
 111         uint32_t                itt;
 112         int                     datadgst;
 113 };
 114
 115 struct iscsi_conn {
 116         struct iscsi_hdr        hdr;            /* header placeholder */
 117         char                    hdrext[4*sizeof(__u16) +
 118                                     sizeof(__u32)];
 119         int                     data_copied;
 120         char                    *data;          /* data placeholder */
 121         struct socket           *sock;          /* TCP socket */
 122         int                     data_size;      /* actual recv_dlength */
 123         int                     stop_stage;     /* conn_stop() flag: *
 124                                                  * stop to recover,  *
 125                                                  * stop to terminate */
 126         /* iSCSI connection-wide sequencing */
 127         uint32_t                exp_statsn;
 128         int                     hdr_size;       /* PDU header size */
 129         unsigned long           suspend_rx;     /* suspend Rx */
 130
 131         struct crypto_tfm       *rx_tfm;        /* CRC32C (Rx) */
 132         struct crypto_tfm       *data_rx_tfm;   /* CRC32C (Rx) for data */
 133
 134         /* control data */
 135         int                     senselen;       /* scsi sense length */
 136         int                     id;             /* CID */
 137         struct iscsi_tcp_recv   in;             /* TCP receive context */
 138         struct iscsi_session    *session;       /* parent session */
 139         struct list_head        item;           /* maintains list of conns */
 140         int                     in_progress;    /* connection state machine */
 141         int                     c_stage;        /* connection state */
 142         struct iscsi_mgmt_task  *login_mtask;   /* mtask used for login/text */
 143         struct iscsi_mgmt_task  *mtask;         /* xmit mtask in progress */
 144         struct iscsi_cmd_task   *ctask;         /* xmit ctask in progress */
 145         spinlock_t              lock;           /* FIXME: to be removed */
 146
 147         /* old values for socket callbacks */
 148         void                    (*old_data_ready)(struct sock *, int);
 149         void                    (*old_state_change)(struct sock *);
 150         void                    (*old_write_space)(struct sock *);
 151
 152         /* xmit */
 153         struct crypto_tfm       *tx_tfm;        /* CRC32C (Tx) */
 154         struct crypto_tfm       *data_tx_tfm;   /* CRC32C (Tx) for data */
 155         struct kfifo            *writequeue;    /* write cmds for Data-Outs */
 156         struct kfifo            *immqueue;      /* immediate xmit queue */
 157         struct kfifo            *mgmtqueue;     /* mgmt (control) xmit queue */
 158         struct kfifo            *xmitqueue;     /* data-path cmd queue */
 159         struct work_struct      xmitwork;       /* per-conn. xmit workqueue */
 160         struct semaphore        xmitsema;       /* serializes connection xmit,
 161                                                  * access to kfifos:      *
 162                                                  * xmitqueue, writequeue, *
 163                                                  * immqueue, mgmtqueue    */
 164         unsigned long           suspend_tx;     /* suspend Tx */
 165
 166         /* abort */
 167         wait_queue_head_t       ehwait;         /* used in eh_abort()     */
 168         struct iscsi_tm         tmhdr;
 169         struct timer_list       tmabort_timer;  /* abort timer */
 170         int                     tmabort_state;  /* see TMABORT_INITIAL, etc.*/
 171
 172         /* negotiated params */
 173         int                     max_recv_dlength;
 174         int                     max_xmit_dlength;
 175         int                     hdrdgst_en;
 176         int                     datadgst_en;
 177
 178         /* MIB-statistics */
 179         uint64_t                txdata_octets;
 180         uint64_t                rxdata_octets;
 181         uint32_t                scsicmd_pdus_cnt;
 182         uint32_t                dataout_pdus_cnt;
 183         uint32_t                scsirsp_pdus_cnt;
 184         uint32_t                datain_pdus_cnt;
 185         uint32_t                r2t_pdus_cnt;
 186         uint32_t                tmfcmd_pdus_cnt;
 187         int32_t                 tmfrsp_pdus_cnt;
 188
 189         /* custom statistics */
 190         uint32_t                sendpage_failures_cnt;
 191         uint32_t                discontiguous_hdr_cnt;
 192         uint32_t                eh_abort_cnt;
 193 };
 194
 195 struct iscsi_session {
 196         /* iSCSI session-wide sequencing */
 197         uint32_t                cmdsn;
 198         uint32_t                exp_cmdsn;
 199         uint32_t                max_cmdsn;
 200
 201         /* configuration */
 202         int                     initial_r2t_en;
 203         int                     max_r2t;
 204         int                     imm_data_en;
 205         int                     first_burst;
 206         int                     max_burst;
 207         int                     time2wait;
 208         int                     time2retain;
 209         int                     pdu_inorder_en;
 210         int                     dataseq_inorder_en;
 211         int                     erl;
 212         int                     ifmarker_en;
 213         int                     ofmarker_en;
 214
 215         /* control data */
 216         struct Scsi_Host        *host;
 217         int                     id;
 218         struct iscsi_conn       *leadconn;      /* leading connection */
 219         spinlock_t              lock;           /* protects session state, *
 220                                                  * sequence numbers,       *
 221                                                  * session resources:      *
 222                                                  * - cmdpool,              *
 223                                                  * - mgmtpool,             *
 224                                                  * - r2tpool               */
 225         int                     state;          /* session state           */
 226         struct list_head        item;
 227         void                    *auth_client;
 228         int                     conn_cnt;
 229         int                     age;            /* counts session re-opens */
 230
 231         struct list_head        connections;    /* list of connections */
 232         int                     cmds_max;       /* size of cmds array */
 233         struct iscsi_cmd_task   **cmds;         /* Original Cmds arr */
 234         struct iscsi_queue      cmdpool;        /* PDU's pool */
 235         int                     mgmtpool_max;   /* size of mgmt array */
 236         struct iscsi_mgmt_task  **mgmt_cmds;    /* Original mgmt arr */
 237         struct iscsi_queue      mgmtpool;       /* Mgmt PDU's pool */
 238 };
 239
 240 struct iscsi_buf {
 241         struct scatterlist      sg;
 242         struct kvec             iov;
 243         unsigned int            sent;
 244 };
 245
 246 struct iscsi_data_task {
 247         struct iscsi_data       hdr;                    /* PDU */
 248         char                    hdrext[sizeof(__u32)];  /* Header-Digest */
 249         struct list_head        item;                   /* data queue item */
 250         struct iscsi_buf        digestbuf;              /* digest buffer */
 251         uint32_t                digest;                 /* data digest */
 252 };
 253 #define ISCSI_DTASK_DEFAULT_MAX ISCSI_SG_TABLESIZE * PAGE_SIZE / 512
 254
 255 struct iscsi_mgmt_task {
 256         struct iscsi_hdr        hdr;            /* mgmt. PDU */
 257         char                    hdrext[sizeof(__u32)];  /* Header-Digest */
 258         char                    *data;          /* mgmt payload */
 259         int                     xmstate;        /* mgmt xmit progress */
 260         int                     data_count;     /* counts data to be sent */
 261         struct iscsi_buf        headbuf;        /* header buffer */
 262         struct iscsi_buf        sendbuf;        /* in progress buffer */
 263         int                     sent;
 264         uint32_t                itt;            /* this ITT */
 265 };
 266
 267 struct iscsi_r2t_info {
 268         __be32                  ttt;            /* copied from R2T */
 269         __be32                  exp_statsn;     /* copied from R2T */
 270         uint32_t                data_length;    /* copied from R2T */
 271         uint32_t                data_offset;    /* copied from R2T */
 272         struct iscsi_buf        headbuf;        /* Data-Out Header Buffer */
 273         struct iscsi_buf        sendbuf;        /* Data-Out in progress buffer*/
 274         int                     sent;           /* R2T sequence progress */
 275         int                     data_count;     /* DATA-Out payload progress */
 276         struct scatterlist      *sg;            /* per-R2T SG list */
 277         int                     solicit_datasn;
 278         struct iscsi_data_task   *dtask;        /* which data task */
 279 };
 280
 281 struct iscsi_cmd_task {
 282         struct iscsi_cmd        hdr;                    /* iSCSI PDU header */
 283         char                    hdrext[4*sizeof(__u16)+ /* AHS */
 284                                     sizeof(__u32)];     /* HeaderDigest */
 285         char                    pad[ISCSI_PAD_LEN];
 286         int                     itt;                    /* this ITT */
 287         int                     datasn;                 /* DataSN */
 288         struct iscsi_buf        headbuf;                /* header buf (xmit) */
 289         struct iscsi_buf        sendbuf;                /* in progress buffer*/
 290         int                     sent;
 291         struct scatterlist      *sg;                    /* per-cmd SG list  */
 292         struct scatterlist      *bad_sg;                /* assert statement */
 293         int                     sg_count;               /* SG's to process  */
 294         uint32_t                unsol_datasn;
 295         uint32_t                exp_r2tsn;
 296         int                     xmstate;                /* xmit xtate machine */
 297         int                     imm_count;              /* imm-data (bytes)   */
 298         int                     unsol_count;            /* unsolicited (bytes)*/
 299         int                     r2t_data_count;         /* R2T Data-Out bytes */
 300         int                     data_count;             /* remaining Data-Out */
 301         int                     pad_count;              /* padded bytes */
 302         struct scsi_cmnd        *sc;                    /* associated SCSI cmd*/
 303         int                     total_length;
 304         int                     data_offset;
 305         struct iscsi_conn       *conn;                  /* used connection    */
 306         struct iscsi_mgmt_task  *mtask;                 /* tmf mtask in progr */
 307
 308         struct iscsi_r2t_info   *r2t;                   /* in progress R2T    */
 309         struct iscsi_queue      r2tpool;
 310         struct kfifo            *r2tqueue;
 311         struct iscsi_r2t_info   **r2ts;
 312         struct list_head        dataqueue;              /* Data-Out dataqueue */
 313         mempool_t               *datapool;
 314         uint32_t                datadigest;             /* for recover digest */
 315         int                     digest_count;
 316         uint32_t                immdigest;              /* for imm data */
 317         struct iscsi_buf        immbuf;                 /* for imm data digest */
 318         struct iscsi_data_task   *dtask;                /* data task in progress*/
 319         int                     digest_offset;          /* for partial buff digest */
 320 };
 321
 322 #endif /* ISCSI_H */