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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 - 2006 Mike Christie
   6  * Copyright (C) 2006 Red Hat, Inc.  All rights reserved.
   7  * maintained by open-iscsi@googlegroups.com
   8  *
   9  * This program is free software; you can redistribute it and/or modify
  10  * it under the terms of the GNU General Public License as published
  11  * by the Free Software Foundation; either version 2 of the License, or
  12  * (at your option) any later version.
  13  *
  14  * This program is distributed in the hope that it will be useful, but
  15  * WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  17  * General Public License for more details.
  18  *
  19  * See the file COPYING included with this distribution for more details.
  20  */
  21
  22 #ifndef ISCSI_TCP_H
  23 #define ISCSI_TCP_H
  24
  25 #include <scsi/libiscsi.h>
  26
  27 /* xmit state machine */
  28 #define XMSTATE_IDLE                    0x0
  29 #define XMSTATE_CMD_HDR_INIT            0x1
  30 #define XMSTATE_CMD_HDR_XMIT            0x2
  31 #define XMSTATE_IMM_HDR                 0x4
  32 #define XMSTATE_IMM_DATA                0x8
  33 #define XMSTATE_UNS_INIT                0x10
  34 #define XMSTATE_UNS_HDR                 0x20
  35 #define XMSTATE_UNS_DATA                0x40
  36 #define XMSTATE_SOL_HDR                 0x80
  37 #define XMSTATE_SOL_DATA                0x100
  38 #define XMSTATE_W_PAD                   0x200
  39 #define XMSTATE_W_RESEND_PAD            0x400
  40 #define XMSTATE_W_RESEND_DATA_DIGEST    0x800
  41 #define XMSTATE_IMM_HDR_INIT            0x1000
  42 #define XMSTATE_SOL_HDR_INIT            0x2000
  43
  44 #define ISCSI_SG_TABLESIZE              SG_ALL
  45 #define ISCSI_TCP_MAX_CMD_LEN           16
  46
  47 struct crypto_hash;
  48 struct socket;
  49 struct iscsi_tcp_conn;
  50 struct iscsi_chunk;
  51
  52 typedef int iscsi_chunk_done_fn_t(struct iscsi_tcp_conn *,
  53                                   struct iscsi_chunk *);
  54
  55 struct iscsi_chunk {
  56         unsigned char           *data;
  57         unsigned int            size;
  58         unsigned int            copied;
  59         unsigned int            total_size;
  60         unsigned int            total_copied;
  61
  62         struct hash_desc        *hash;
  63         unsigned char           recv_digest[ISCSI_DIGEST_SIZE];
  64         unsigned char           digest[ISCSI_DIGEST_SIZE];
  65         unsigned int            digest_len;
  66
  67         struct scatterlist      *sg;
  68         void                    *sg_mapped;
  69         unsigned int            sg_offset;
  70         unsigned int            sg_index;
  71         unsigned int            sg_count;
  72
  73         iscsi_chunk_done_fn_t   *done;
  74 };
  75
  76 /* Socket connection recieve helper */
  77 struct iscsi_tcp_recv {
  78         struct iscsi_hdr        *hdr;
  79         struct iscsi_chunk      chunk;
  80
  81         /* Allocate buffer for BHS + AHS */
  82         uint32_t                hdr_buf[64];
  83
  84         /* copied and flipped values */
  85         int                     datalen;
  86 };
  87
  88 /* Socket connection send helper */
  89 struct iscsi_tcp_send {
  90         struct iscsi_hdr        *hdr;
  91         struct iscsi_chunk      chunk;
  92         struct iscsi_chunk      data_chunk;
  93
  94         /* Allocate buffer for BHS + AHS */
  95         uint32_t                hdr_buf[64];
  96 };
  97
  98 struct iscsi_tcp_conn {
  99         struct iscsi_conn       *iscsi_conn;
 100         struct socket           *sock;
 101         int                     stop_stage;     /* conn_stop() flag: *
 102                                                  * stop to recover,  *
 103                                                  * stop to terminate */
 104         /* control data */
 105         struct iscsi_tcp_recv   in;             /* TCP receive context */
 106         struct iscsi_tcp_send   out;            /* TCP send context */
 107
 108         /* old values for socket callbacks */
 109         void                    (*old_data_ready)(struct sock *, int);
 110         void                    (*old_state_change)(struct sock *);
 111         void                    (*old_write_space)(struct sock *);
 112
 113         /* data and header digests */
 114         struct hash_desc        tx_hash;        /* CRC32C (Tx) */
 115         struct hash_desc        rx_hash;        /* CRC32C (Rx) */
 116
 117         /* MIB custom statistics */
 118         uint32_t                sendpage_failures_cnt;
 119         uint32_t                discontiguous_hdr_cnt;
 120
 121         ssize_t (*sendpage)(struct socket *, struct page *, int, size_t, int);
 122 };
 123
 124 struct iscsi_buf {
 125         struct scatterlist      sg;
 126         unsigned int            sent;
 127         char                    use_sendmsg;
 128 };
 129
 130 struct iscsi_data_task {
 131         struct iscsi_data       hdr;                    /* PDU */
 132         char                    hdrext[ISCSI_DIGEST_SIZE];/* Header-Digest */
 133         struct iscsi_buf        digestbuf;              /* digest buffer */
 134         uint32_t                digest;                 /* data digest */
 135 };
 136
 137 struct iscsi_tcp_mgmt_task {
 138         struct iscsi_hdr        hdr;
 139         char                    hdrext[ISCSI_DIGEST_SIZE]; /* Header-Digest */
 140         int                     xmstate;        /* mgmt xmit progress */
 141         struct iscsi_buf        headbuf;        /* header buffer */
 142         struct iscsi_buf        sendbuf;        /* in progress buffer */
 143         int                     sent;
 144 };
 145
 146 struct iscsi_r2t_info {
 147         __be32                  ttt;            /* copied from R2T */
 148         __be32                  exp_statsn;     /* copied from R2T */
 149         uint32_t                data_length;    /* copied from R2T */
 150         uint32_t                data_offset;    /* copied from R2T */
 151         struct iscsi_buf        headbuf;        /* Data-Out Header Buffer */
 152         struct iscsi_buf        sendbuf;        /* Data-Out in progress buffer*/
 153         int                     sent;           /* R2T sequence progress */
 154         int                     data_count;     /* DATA-Out payload progress */
 155         struct scatterlist      *sg;            /* per-R2T SG list */
 156         int                     solicit_datasn;
 157         struct iscsi_data_task   dtask;        /* which data task */
 158 };
 159
 160 struct iscsi_tcp_cmd_task {
 161         struct iscsi_hdr_buff {
 162                 struct iscsi_cmd        cmd_hdr;
 163                 char                    hdrextbuf[ISCSI_MAX_AHS_SIZE +
 164                                                   ISCSI_DIGEST_SIZE];
 165         } hdr;
 166         char                    pad[ISCSI_PAD_LEN];
 167         int                     pad_count;              /* padded bytes */
 168         struct iscsi_buf        headbuf;                /* header buf (xmit) */
 169         struct iscsi_buf        sendbuf;                /* in progress buffer*/
 170         int                     xmstate;                /* xmit xtate machine */
 171         int                     sent;
 172         struct scatterlist      *sg;                    /* per-cmd SG list  */
 173         struct scatterlist      *bad_sg;                /* assert statement */
 174         int                     sg_count;               /* SG's to process  */
 175         uint32_t                exp_datasn;             /* expected target's R2TSN/DataSN */
 176         int                     data_offset;
 177         struct iscsi_r2t_info   *r2t;                   /* in progress R2T    */
 178         struct iscsi_queue      r2tpool;
 179         struct kfifo            *r2tqueue;
 180         struct iscsi_r2t_info   **r2ts;
 181         int                     digest_count;
 182         uint32_t                immdigest;              /* for imm data */
 183         struct iscsi_buf        immbuf;                 /* for imm data digest */
 184         struct iscsi_data_task  unsol_dtask;    /* unsol data task */
 185 };
 186
 187 #endif /* ISCSI_H */