/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
 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
 51	iscsi_segment_done_fn_t	*done;
 52};
 53
 54/* Socket connection recieve helper */
 55struct iscsi_tcp_recv {
 56	struct iscsi_hdr	*hdr;
 57	struct iscsi_segment	segment;
 58
 59	/* Allocate buffer for BHS + AHS */
 60	uint32_t		hdr_buf[64];
 61
 62	/* copied and flipped values */
 63	int			datalen;
 64};
 65
 66struct iscsi_tcp_conn {
 67	struct iscsi_conn	*iscsi_conn;
 68	void			*dd_data;
 69	int			stop_stage;	/* conn_stop() flag: *
 70						 * stop to recover,  *
 71						 * stop to terminate */
 72	/* control data */
 73	struct iscsi_tcp_recv	in;		/* TCP receive context */
 74	/* CRC32C (Rx) LLD should set this is they do not offload */
 75	struct hash_desc	*rx_hash;
 76};
 77
 78struct iscsi_tcp_task {
 79	uint32_t		exp_datasn;	/* expected target's R2TSN/DataSN */
 80	int			data_offset;
 81	struct iscsi_r2t_info	*r2t;		/* in progress solict R2T */
 82	struct iscsi_pool	r2tpool;
 83	struct kfifo		r2tqueue;
 84	void			*dd_data;
 85};
 86
 87enum {
 88	ISCSI_TCP_SEGMENT_DONE,		/* curr seg has been processed */
 89	ISCSI_TCP_SKB_DONE,		/* skb is out of data */
 90	ISCSI_TCP_CONN_ERR,		/* iscsi layer has fired a conn err */
 91	ISCSI_TCP_SUSPENDED,		/* conn is suspended */
 92};
 93
 94extern void iscsi_tcp_hdr_recv_prep(struct iscsi_tcp_conn *tcp_conn);
 95extern int iscsi_tcp_recv_skb(struct iscsi_conn *conn, struct sk_buff *skb,
 96			      unsigned int offset, bool offloaded, int *status);
 97extern void iscsi_tcp_cleanup_task(struct iscsi_task *task);
 98extern int iscsi_tcp_task_init(struct iscsi_task *task);
 99extern int iscsi_tcp_task_xmit(struct iscsi_task *task);
100
101/* segment helpers */
102extern int iscsi_tcp_recv_segment_is_hdr(struct iscsi_tcp_conn *tcp_conn);
103extern int iscsi_tcp_segment_done(struct iscsi_tcp_conn *tcp_conn,
104				  struct iscsi_segment *segment, int recv,
105				  unsigned copied);
106extern void iscsi_tcp_segment_unmap(struct iscsi_segment *segment);
107
108extern void iscsi_segment_init_linear(struct iscsi_segment *segment,
109				      void *data, size_t size,
110				      iscsi_segment_done_fn_t *done,
111				      struct hash_desc *hash);
112extern int
113iscsi_segment_seek_sg(struct iscsi_segment *segment,
114		      struct scatterlist *sg_list, unsigned int sg_count,
115		      unsigned int offset, size_t size,
116		      iscsi_segment_done_fn_t *done, struct hash_desc *hash);
117
118/* digest helpers */
119extern void iscsi_tcp_dgst_header(struct hash_desc *hash, const void *hdr,
120				  size_t hdrlen,
121				  unsigned char digest[ISCSI_DIGEST_SIZE]);
122extern struct iscsi_cls_conn *
123iscsi_tcp_conn_setup(struct iscsi_cls_session *cls_session, int dd_data_size,
124		     uint32_t conn_idx);
125extern void iscsi_tcp_conn_teardown(struct iscsi_cls_conn *cls_conn);
126
127/* misc helpers */
128extern int iscsi_tcp_r2tpool_alloc(struct iscsi_session *session);
129extern void iscsi_tcp_r2tpool_free(struct iscsi_session *session);
130
131extern void iscsi_tcp_conn_get_stats(struct iscsi_cls_conn *cls_conn,
132				     struct iscsi_stats *stats);
133#endif /* LIBISCSI_TCP_H */