include/scsi/libiscsi_tcp.h

   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
  26 struct iscsi_tcp_conn;
  27 struct iscsi_segment;
  28 struct sk_buff;
  29 struct hash_desc;
  30
  31 typedef int iscsi_segment_done_fn_t(struct iscsi_tcp_conn *,
  32                                     struct iscsi_segment *);
  33
  34 struct 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 */
  56 struct 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
  67 struct 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
  79 struct 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
  88 enum {
  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
  95 extern void iscsi_tcp_hdr_recv_prep(struct iscsi_tcp_conn *tcp_conn);
  96 extern int iscsi_tcp_recv_skb(struct iscsi_conn *conn, struct sk_buff *skb,
  97                               unsigned int offset, bool offloaded, int *status);
  98 extern void iscsi_tcp_cleanup_task(struct iscsi_task *task);
  99 extern int iscsi_tcp_task_init(struct iscsi_task *task);
 100 extern int iscsi_tcp_task_xmit(struct iscsi_task *task);
 101
 102 /* segment helpers */
 103 extern int iscsi_tcp_recv_segment_is_hdr(struct iscsi_tcp_conn *tcp_conn);
 104 extern int iscsi_tcp_segment_done(struct iscsi_tcp_conn *tcp_conn,
 105                                   struct iscsi_segment *segment, int recv,
 106                                   unsigned copied);
 107 extern void iscsi_tcp_segment_unmap(struct iscsi_segment *segment);
 108
 109 extern 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);
 113 extern int
 114 iscsi_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 */
 120 extern void iscsi_tcp_dgst_header(struct hash_desc *hash, const void *hdr,
 121                                   size_t hdrlen,
 122                                   unsigned char digest[ISCSI_DIGEST_SIZE]);
 123 extern struct iscsi_cls_conn *
 124 iscsi_tcp_conn_setup(struct iscsi_cls_session *cls_session, int dd_data_size,
 125                      uint32_t conn_idx);
 126 extern void iscsi_tcp_conn_teardown(struct iscsi_cls_conn *cls_conn);
 127
 128 /* misc helpers */
 129 extern int iscsi_tcp_r2tpool_alloc(struct iscsi_session *session);
 130 extern void iscsi_tcp_r2tpool_free(struct iscsi_session *session);
 131
 132 extern void iscsi_tcp_conn_get_stats(struct iscsi_cls_conn *cls_conn,
 133                                      struct iscsi_stats *stats);
 134 #endif /* LIBISCSI_TCP_H */