[SCSI] iscsi_tcp: split module into lib and lld

/*

 * iSCSI over TCP/IP Data-Path lib

 *

 * Copyright (C) 2008 Mike Christie

 * Copyright (C) 2008 Red Hat, Inc.  All rights reserved.

 * maintained by open-iscsi@googlegroups.com

 *

 * This program is free software; you can redistribute it and/or modify

 * it under the terms of the GNU General Public License as published

 * by the Free Software Foundation; either version 2 of the License, or

 * (at your option) any later version.

 *

 * This program is distributed in the hope that it will be useful, but

 * WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU

 * General Public License for more details.

 *

 * See the file COPYING included with this distribution for more details.

 */

#ifndef LIBISCSI_TCP_H

#define LIBISCSI_TCP_H

#include <scsi/libiscsi.h>

struct iscsi_tcp_conn;

struct iscsi_segment;

struct sk_buff;

struct hash_desc;

typedef int iscsi_segment_done_fn_t(struct iscsi_tcp_conn *,

				    struct iscsi_segment *);

struct iscsi_segment {

	unsigned char		*data;

	unsigned int		size;

	unsigned int		copied;

	unsigned int		total_size;

	unsigned int		total_copied;

	struct hash_desc	*hash;

	unsigned char		recv_digest[ISCSI_DIGEST_SIZE];

	unsigned char		digest[ISCSI_DIGEST_SIZE];

	unsigned int		digest_len;

	struct scatterlist	*sg;

	void			*sg_mapped;

	unsigned int		sg_offset;

	iscsi_segment_done_fn_t	*done;

};

/* Socket connection recieve helper */

struct iscsi_tcp_recv {

	struct iscsi_hdr	*hdr;

	struct iscsi_segment	segment;

	/* Allocate buffer for BHS + AHS */

	uint32_t		hdr_buf[64];

	/* copied and flipped values */

	int			datalen;

};

struct iscsi_tcp_conn {

	struct iscsi_conn	*iscsi_conn;

	void			*dd_data;

	int			stop_stage;	/* conn_stop() flag: *

						 * stop to recover,  *

						 * stop to terminate */

	/* control data */

	struct iscsi_tcp_recv	in;		/* TCP receive context */

	/* CRC32C (Rx) LLD should set this is they do not offload */

	struct hash_desc	*rx_hash;

};

struct iscsi_tcp_task {

	uint32_t		exp_datasn;	/* expected target's R2TSN/DataSN */

	int			data_offset;

	struct iscsi_r2t_info	*r2t;		/* in progress solict R2T */

	struct iscsi_pool	r2tpool;

	struct kfifo		*r2tqueue;

	void			*dd_data;

};

enum {

	ISCSI_TCP_SEGMENT_DONE,		/* curr seg has been processed */

	ISCSI_TCP_SKB_DONE,		/* skb is out of data */

	ISCSI_TCP_CONN_ERR,		/* iscsi layer has fired a conn err */

	ISCSI_TCP_SUSPENDED,		/* conn is suspended */

};

extern void iscsi_tcp_hdr_recv_prep(struct iscsi_tcp_conn *tcp_conn);

extern int iscsi_tcp_recv_skb(struct iscsi_conn *conn, struct sk_buff *skb,

			      unsigned int offset, bool offloaded, int *status);

extern void iscsi_tcp_cleanup_task(struct iscsi_task *task);

extern int iscsi_tcp_task_init(struct iscsi_task *task);

extern int iscsi_tcp_task_xmit(struct iscsi_task *task);

/* segment helpers */

extern int iscsi_tcp_recv_segment_is_hdr(struct iscsi_tcp_conn *tcp_conn);

extern int iscsi_tcp_segment_done(struct iscsi_segment *segment, int recv,

				  unsigned copied);

extern void iscsi_tcp_segment_unmap(struct iscsi_segment *segment);

extern void iscsi_segment_init_linear(struct iscsi_segment *segment,

				      void *data, size_t size,

				      iscsi_segment_done_fn_t *done,

				      struct hash_desc *hash);

extern int

iscsi_segment_seek_sg(struct iscsi_segment *segment,

		      struct scatterlist *sg_list, unsigned int sg_count,

		      unsigned int offset, size_t size,

		      iscsi_segment_done_fn_t *done, struct hash_desc *hash);

/* digest helpers */

extern void iscsi_tcp_dgst_header(struct hash_desc *hash, const void *hdr,

				  size_t hdrlen,

				  unsigned char digest[ISCSI_DIGEST_SIZE]);

extern struct iscsi_cls_conn *

iscsi_tcp_conn_setup(struct iscsi_cls_session *cls_session, int dd_data_size,

		     uint32_t conn_idx);

extern void iscsi_tcp_conn_teardown(struct iscsi_cls_conn *cls_conn);

/* misc helpers */

extern int iscsi_tcp_r2tpool_alloc(struct iscsi_session *session);

extern void iscsi_tcp_r2tpool_free(struct iscsi_session *session);

extern void iscsi_tcp_conn_get_stats(struct iscsi_cls_conn *cls_conn,

				     struct iscsi_stats *stats);

#endif /* LIBISCSI_TCP_H */