linux/include/scsi/libiscsi_tcp.h
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   1/*
   2 * iSCSI over TCP/IP Data-Path lib
   3 *
   4 * Copyright (C) 2008 Mike Christie
   5 * Copyright (C) 2008 Red Hat, Inc.  All rights reserved.
   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 LIBISCSI_TCP_H
  22#define LIBISCSI_TCP_H
  23
  24#include <scsi/libiscsi.h>
  25
  26struct iscsi_tcp_conn;
  27struct iscsi_segment;
  28struct sk_buff;
  29struct hash_desc;
  30
  31typedef int iscsi_segment_done_fn_t(struct iscsi_tcp_conn *,
  32                                    struct iscsi_segment *);
  33
  34struct iscsi_segment {
  35        unsigned char           *data;
  36        unsigned int            size;
  37        unsigned int            copied;
  38        unsigned int            total_size;
  39        unsigned int            total_copied;
  40
  41        struct hash_desc        *hash;
  42        unsigned char           padbuf[ISCSI_PAD_LEN];
  43        unsigned char           recv_digest[ISCSI_DIGEST_SIZE];
  44        unsigned char           digest[ISCSI_DIGEST_SIZE];
  45        unsigned int            digest_len;
  46
  47        struct scatterlist      *sg;
  48        void                    *sg_mapped;
  49        unsigned int            sg_offset;
  50        bool                    atomic_mapped;
  51
  52        iscsi_segment_done_fn_t *done;
  53};
  54
  55/* Socket connection receive helper */
  56struct iscsi_tcp_recv {
  57        struct iscsi_hdr        *hdr;
  58        struct iscsi_segment    segment;
  59
  60        /* Allocate buffer for BHS + AHS */
  61        uint32_t                hdr_buf[64];
  62
  63        /* copied and flipped values */
  64        int                     datalen;
  65};
  66
  67struct iscsi_tcp_conn {
  68        struct iscsi_conn       *iscsi_conn;
  69        void                    *dd_data;
  70        int                     stop_stage;     /* conn_stop() flag: *
  71                                                 * stop to recover,  *
  72                                                 * stop to terminate */
  73        /* control data */
  74        struct iscsi_tcp_recv   in;             /* TCP receive context */
  75        /* CRC32C (Rx) LLD should set this is they do not offload */
  76        struct hash_desc        *rx_hash;
  77};
  78
  79struct iscsi_tcp_task {
  80        uint32_t                exp_datasn;     /* expected target's R2TSN/DataSN */
  81        int                     data_offset;
  82        struct iscsi_r2t_info   *r2t;           /* in progress solict R2T */
  83        struct iscsi_pool       r2tpool;
  84        struct kfifo            r2tqueue;
  85        void                    *dd_data;
  86};
  87
  88enum {
  89        ISCSI_TCP_SEGMENT_DONE,         /* curr seg has been processed */
  90        ISCSI_TCP_SKB_DONE,             /* skb is out of data */
  91        ISCSI_TCP_CONN_ERR,             /* iscsi layer has fired a conn err */
  92        ISCSI_TCP_SUSPENDED,            /* conn is suspended */
  93};
  94
  95extern void iscsi_tcp_hdr_recv_prep(struct iscsi_tcp_conn *tcp_conn);
  96extern int iscsi_tcp_recv_skb(struct iscsi_conn *conn, struct sk_buff *skb,
  97                              unsigned int offset, bool offloaded, int *status);
  98extern void iscsi_tcp_cleanup_task(struct iscsi_task *task);
  99extern int iscsi_tcp_task_init(struct iscsi_task *task);
 100extern int iscsi_tcp_task_xmit(struct iscsi_task *task);
 101
 102/* segment helpers */
 103extern int iscsi_tcp_recv_segment_is_hdr(struct iscsi_tcp_conn *tcp_conn);
 104extern int iscsi_tcp_segment_done(struct iscsi_tcp_conn *tcp_conn,
 105                                  struct iscsi_segment *segment, int recv,
 106                                  unsigned copied);
 107extern void iscsi_tcp_segment_unmap(struct iscsi_segment *segment);
 108
 109extern void iscsi_segment_init_linear(struct iscsi_segment *segment,
 110                                      void *data, size_t size,
 111                                      iscsi_segment_done_fn_t *done,
 112                                      struct hash_desc *hash);
 113extern int
 114iscsi_segment_seek_sg(struct iscsi_segment *segment,
 115                      struct scatterlist *sg_list, unsigned int sg_count,
 116                      unsigned int offset, size_t size,
 117                      iscsi_segment_done_fn_t *done, struct hash_desc *hash);
 118
 119/* digest helpers */
 120extern void iscsi_tcp_dgst_header(struct hash_desc *hash, const void *hdr,
 121                                  size_t hdrlen,
 122                                  unsigned char digest[ISCSI_DIGEST_SIZE]);
 123extern struct iscsi_cls_conn *
 124iscsi_tcp_conn_setup(struct iscsi_cls_session *cls_session, int dd_data_size,
 125                     uint32_t conn_idx);
 126extern void iscsi_tcp_conn_teardown(struct iscsi_cls_conn *cls_conn);
 127
 128/* misc helpers */
 129extern int iscsi_tcp_r2tpool_alloc(struct iscsi_session *session);
 130extern void iscsi_tcp_r2tpool_free(struct iscsi_session *session);
 131extern int iscsi_tcp_set_max_r2t(struct iscsi_conn *conn, char *buf);
 132extern void iscsi_tcp_conn_get_stats(struct iscsi_cls_conn *cls_conn,
 133                                     struct iscsi_stats *stats);
 134#endif /* LIBISCSI_TCP_H */
 135
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