root/include/scsi/libiscsi_tcp.h

INCLUDED FROM

   1 /* SPDX-License-Identifier: GPL-2.0-or-later */
   2 /*
   3  * iSCSI over TCP/IP Data-Path lib
   4  *
   5  * Copyright (C) 2008 Mike Christie
   6  * Copyright (C) 2008 Red Hat, Inc.  All rights reserved.
   7  * maintained by open-iscsi@googlegroups.com
   8  */
   9 
  10 #ifndef LIBISCSI_TCP_H
  11 #define LIBISCSI_TCP_H
  12 
  13 #include <scsi/libiscsi.h>
  14 
  15 struct iscsi_tcp_conn;
  16 struct iscsi_segment;
  17 struct sk_buff;
  18 struct ahash_request;
  19 
  20 typedef int iscsi_segment_done_fn_t(struct iscsi_tcp_conn *,
  21                                     struct iscsi_segment *);
  22 
  23 struct iscsi_segment {
  24         unsigned char           *data;
  25         unsigned int            size;
  26         unsigned int            copied;
  27         unsigned int            total_size;
  28         unsigned int            total_copied;
  29 
  30         struct ahash_request    *hash;
  31         unsigned char           padbuf[ISCSI_PAD_LEN];
  32         unsigned char           recv_digest[ISCSI_DIGEST_SIZE];
  33         unsigned char           digest[ISCSI_DIGEST_SIZE];
  34         unsigned int            digest_len;
  35 
  36         struct scatterlist      *sg;
  37         void                    *sg_mapped;
  38         unsigned int            sg_offset;
  39         bool                    atomic_mapped;
  40 
  41         iscsi_segment_done_fn_t *done;
  42 };
  43 
  44 /* Socket connection receive helper */
  45 struct iscsi_tcp_recv {
  46         struct iscsi_hdr        *hdr;
  47         struct iscsi_segment    segment;
  48 
  49         /* Allocate buffer for BHS + AHS */
  50         uint32_t                hdr_buf[64];
  51 
  52         /* copied and flipped values */
  53         int                     datalen;
  54 };
  55 
  56 struct iscsi_tcp_conn {
  57         struct iscsi_conn       *iscsi_conn;
  58         void                    *dd_data;
  59         int                     stop_stage;     /* conn_stop() flag: *
  60                                                  * stop to recover,  *
  61                                                  * stop to terminate */
  62         /* control data */
  63         struct iscsi_tcp_recv   in;             /* TCP receive context */
  64         /* CRC32C (Rx) LLD should set this is they do not offload */
  65         struct ahash_request    *rx_hash;
  66 };
  67 
  68 struct iscsi_tcp_task {
  69         uint32_t                exp_datasn;     /* expected target's R2TSN/DataSN */
  70         int                     data_offset;
  71         struct iscsi_r2t_info   *r2t;           /* in progress solict R2T */
  72         struct iscsi_pool       r2tpool;
  73         struct kfifo            r2tqueue;
  74         void                    *dd_data;
  75         spinlock_t              pool2queue;
  76         spinlock_t              queue2pool;
  77 };
  78 
  79 enum {
  80         ISCSI_TCP_SEGMENT_DONE,         /* curr seg has been processed */
  81         ISCSI_TCP_SKB_DONE,             /* skb is out of data */
  82         ISCSI_TCP_CONN_ERR,             /* iscsi layer has fired a conn err */
  83         ISCSI_TCP_SUSPENDED,            /* conn is suspended */
  84 };
  85 
  86 extern void iscsi_tcp_hdr_recv_prep(struct iscsi_tcp_conn *tcp_conn);
  87 extern int iscsi_tcp_recv_skb(struct iscsi_conn *conn, struct sk_buff *skb,
  88                               unsigned int offset, bool offloaded, int *status);
  89 extern void iscsi_tcp_cleanup_task(struct iscsi_task *task);
  90 extern int iscsi_tcp_task_init(struct iscsi_task *task);
  91 extern int iscsi_tcp_task_xmit(struct iscsi_task *task);
  92 
  93 /* segment helpers */
  94 extern int iscsi_tcp_recv_segment_is_hdr(struct iscsi_tcp_conn *tcp_conn);
  95 extern int iscsi_tcp_segment_done(struct iscsi_tcp_conn *tcp_conn,
  96                                   struct iscsi_segment *segment, int recv,
  97                                   unsigned copied);
  98 extern void iscsi_tcp_segment_unmap(struct iscsi_segment *segment);
  99 
 100 extern void iscsi_segment_init_linear(struct iscsi_segment *segment,
 101                                       void *data, size_t size,
 102                                       iscsi_segment_done_fn_t *done,
 103                                       struct ahash_request *hash);
 104 extern int
 105 iscsi_segment_seek_sg(struct iscsi_segment *segment,
 106                       struct scatterlist *sg_list, unsigned int sg_count,
 107                       unsigned int offset, size_t size,
 108                       iscsi_segment_done_fn_t *done,
 109                       struct ahash_request *hash);
 110 
 111 /* digest helpers */
 112 extern void iscsi_tcp_dgst_header(struct ahash_request *hash, const void *hdr,
 113                                   size_t hdrlen,
 114                                   unsigned char digest[ISCSI_DIGEST_SIZE]);
 115 extern struct iscsi_cls_conn *
 116 iscsi_tcp_conn_setup(struct iscsi_cls_session *cls_session, int dd_data_size,
 117                      uint32_t conn_idx);
 118 extern void iscsi_tcp_conn_teardown(struct iscsi_cls_conn *cls_conn);
 119 
 120 /* misc helpers */
 121 extern int iscsi_tcp_r2tpool_alloc(struct iscsi_session *session);
 122 extern void iscsi_tcp_r2tpool_free(struct iscsi_session *session);
 123 extern int iscsi_tcp_set_max_r2t(struct iscsi_conn *conn, char *buf);
 124 extern void iscsi_tcp_conn_get_stats(struct iscsi_cls_conn *cls_conn,
 125                                      struct iscsi_stats *stats);
 126 #endif /* LIBISCSI_TCP_H */