LXR linux/include/scsi/libiscsi

   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
  15struct iscsi_tcp_conn;
  16struct iscsi_segment;
  17struct sk_buff;
  18struct ahash_request;
  19
  20typedef int iscsi_segment_done_fn_t(struct iscsi_tcp_conn *,
  21                                    struct iscsi_segment *);
  22
  23struct 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 */
  45struct 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
  56struct 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
  68struct 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
  79enum {
  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
  86extern void iscsi_tcp_hdr_recv_prep(struct iscsi_tcp_conn *tcp_conn);
  87extern int iscsi_tcp_recv_skb(struct iscsi_conn *conn, struct sk_buff *skb,
  88                              unsigned int offset, bool offloaded, int *status);
  89extern void iscsi_tcp_cleanup_task(struct iscsi_task *task);
  90extern int iscsi_tcp_task_init(struct iscsi_task *task);
  91extern int iscsi_tcp_task_xmit(struct iscsi_task *task);
  92
  93/* segment helpers */
  94extern int iscsi_tcp_recv_segment_is_hdr(struct iscsi_tcp_conn *tcp_conn);
  95extern int iscsi_tcp_segment_done(struct iscsi_tcp_conn *tcp_conn,
  96                                  struct iscsi_segment *segment, int recv,
  97                                  unsigned copied);
  98extern void iscsi_tcp_segment_unmap(struct iscsi_segment *segment);
  99
 100extern 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);
 104extern int
 105iscsi_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 */
 112extern void iscsi_tcp_dgst_header(struct ahash_request *hash, const void *hdr,
 113                                  size_t hdrlen,
 114                                  unsigned char digest[ISCSI_DIGEST_SIZE]);
 115extern struct iscsi_cls_conn *
 116iscsi_tcp_conn_setup(struct iscsi_cls_session *cls_session, int dd_data_size,
 117                     uint32_t conn_idx);
 118extern void iscsi_tcp_conn_teardown(struct iscsi_cls_conn *cls_conn);
 119
 120/* misc helpers */
 121extern int iscsi_tcp_r2tpool_alloc(struct iscsi_session *session);
 122extern void iscsi_tcp_r2tpool_free(struct iscsi_session *session);
 123extern int iscsi_tcp_set_max_r2t(struct iscsi_conn *conn, char *buf);
 124extern void iscsi_tcp_conn_get_stats(struct iscsi_cls_conn *cls_conn,
 125                                     struct iscsi_stats *stats);
 126#endif /* LIBISCSI_TCP_H */
 127