[SCSI] open-iscsi/linux-iscsi-5 Initiator: Initiator header

/*

 * iSCSI Initiator TCP Transport

 * Copyright (C) 2004 Dmitry Yusupov

 * Copyright (C) 2004 Alex Aizman

 * Copyright (C) 2005 Mike Christie

 * 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 ISCSI_TCP_H

#define ISCSI_TCP_H

/* Session's states */

#define ISCSI_STATE_FREE		1

#define ISCSI_STATE_LOGGED_IN		2

#define ISCSI_STATE_FAILED		3

#define ISCSI_STATE_TERMINATE		4

/* Connection's states */

#define ISCSI_CONN_INITIAL_STAGE	0

#define ISCSI_CONN_STARTED		1

#define ISCSI_CONN_STOPPED		2

#define ISCSI_CONN_CLEANUP_WAIT		3

/* Connection suspend "bit" */

#define SUSPEND_BIT			1

/* Socket's Receive state machine */

#define IN_PROGRESS_WAIT_HEADER		0x0

#define IN_PROGRESS_HEADER_GATHER	0x1

#define IN_PROGRESS_DATA_RECV		0x2

#define IN_PROGRESS_DDIGEST_RECV	0x3

/* Task Mgmt states */

#define	TMABORT_INITIAL			0x0

#define	TMABORT_SUCCESS			0x1

#define	TMABORT_FAILED			0x2

#define	TMABORT_TIMEDOUT		0x3

/* xmit state machine */

#define	XMSTATE_IDLE			0x0

#define	XMSTATE_R_HDR			0x1

#define	XMSTATE_W_HDR			0x2

#define	XMSTATE_IMM_HDR			0x4

#define	XMSTATE_IMM_DATA		0x8

#define	XMSTATE_UNS_INIT		0x10

#define	XMSTATE_UNS_HDR			0x20

#define	XMSTATE_UNS_DATA		0x40

#define	XMSTATE_SOL_HDR			0x80

#define	XMSTATE_SOL_DATA		0x100

#define	XMSTATE_W_PAD			0x200

#define XMSTATE_DATA_DIGEST		0x400

#define ISCSI_CONN_MAX			1

#define ISCSI_CONN_RCVBUF_MIN		262144

#define ISCSI_CONN_SNDBUF_MIN		262144

#define ISCSI_PAD_LEN			4

#define ISCSI_R2T_MAX			16

#define ISCSI_XMIT_CMDS_MAX		128	/* must be power of 2 */

#define ISCSI_MGMT_CMDS_MAX		32	/* must be power of 2 */

#define ISCSI_MGMT_ITT_OFFSET		0xa00

#define ISCSI_SG_TABLESIZE		SG_ALL

#define ISCSI_CMD_PER_LUN		128

#define ISCSI_TCP_MAX_CMD_LEN		16

#define ITT_MASK			(0xfff)

#define CID_SHIFT			12

#define CID_MASK			(0xffff<<CID_SHIFT)

#define AGE_SHIFT			28

#define AGE_MASK			(0xf<<AGE_SHIFT)

struct iscsi_queue {

	struct kfifo		*queue;		/* FIFO Queue */

	void			**pool;		/* Pool of elements */

	int			max;		/* Max number of elements */

};

struct iscsi_session;

struct iscsi_cmd_task;

struct iscsi_mgmt_task;

/* Socket connection recieve helper */

struct iscsi_tcp_recv {

	struct iscsi_hdr	*hdr;

	struct sk_buff		*skb;

	int			offset;

	int			len;

	int			hdr_offset;

	int			copy;

	int			copied;

	int			padding;

	struct iscsi_cmd_task	*ctask;		/* current cmd in progress */

	/* copied and flipped values */

	int			opcode;

	int			flags;

	int			cmd_status;

	int			ahslen;

	int			datalen;

	uint32_t		itt;

	int			datadgst;

};

struct iscsi_conn {

	struct iscsi_hdr	hdr;		/* header placeholder */

	char			hdrext[4*sizeof(__u16) +

				    sizeof(__u32)];

	int			data_copied;

	char			*data;		/* data placeholder */

	struct socket           *sock;          /* TCP socket */

	int			data_size;	/* actual recv_dlength */

	int			stop_stage;	/* conn_stop() flag: *

						 * stop to recover,  *

						 * stop to terminate */

	/* iSCSI connection-wide sequencing */

	uint32_t		exp_statsn;

	int			hdr_size;	/* PDU header size */

	unsigned long		suspend_rx;	/* suspend Rx */

	struct crypto_tfm	*rx_tfm;	/* CRC32C (Rx) */

	struct crypto_tfm	*data_rx_tfm;	/* CRC32C (Rx) for data */

	/* control data */

	int			senselen;	/* scsi sense length */

	int			id;		/* CID */

	struct iscsi_tcp_recv	in;		/* TCP receive context */

	struct iscsi_session	*session;	/* parent session */

	struct list_head	item;		/* maintains list of conns */

	int			in_progress;	/* connection state machine */

	int			c_stage;	/* connection state */

	struct iscsi_mgmt_task	*login_mtask;	/* mtask used for login/text */

	struct iscsi_mgmt_task	*mtask;		/* xmit mtask in progress */

	struct iscsi_cmd_task	*ctask;		/* xmit ctask in progress */

	spinlock_t		lock;		/* FIXME: to be removed */

	/* old values for socket callbacks */

	void			(*old_data_ready)(struct sock *, int);

	void			(*old_state_change)(struct sock *);

	void			(*old_write_space)(struct sock *);

	/* xmit */

	struct crypto_tfm	*tx_tfm;	/* CRC32C (Tx) */

	struct crypto_tfm	*data_tx_tfm;	/* CRC32C (Tx) for data */

	struct kfifo		*writequeue;	/* write cmds for Data-Outs */

	struct kfifo		*immqueue;	/* immediate xmit queue */

	struct kfifo		*mgmtqueue;	/* mgmt (control) xmit queue */

	struct kfifo		*xmitqueue;	/* data-path cmd queue */

	struct work_struct	xmitwork;	/* per-conn. xmit workqueue */

	struct semaphore	xmitsema;	/* serializes connection xmit,

						 * access to kfifos:	  *

						 * xmitqueue, writequeue, *

						 * immqueue, mgmtqueue    */

	unsigned long		suspend_tx;	/* suspend Tx */

	/* abort */

	wait_queue_head_t	ehwait;		/* used in eh_abort()     */

	struct iscsi_tm		tmhdr;

	struct timer_list	tmabort_timer;  /* abort timer */

	int			tmabort_state;  /* see TMABORT_INITIAL, etc.*/

	/* negotiated params */

	int			max_recv_dlength;

	int			max_xmit_dlength;

	int			hdrdgst_en;

	int			datadgst_en;

	/* MIB-statistics */

	uint64_t		txdata_octets;

	uint64_t		rxdata_octets;

	uint32_t		scsicmd_pdus_cnt;

	uint32_t		dataout_pdus_cnt;

	uint32_t		scsirsp_pdus_cnt;

	uint32_t		datain_pdus_cnt;

	uint32_t		r2t_pdus_cnt;

	uint32_t		tmfcmd_pdus_cnt;

	int32_t			tmfrsp_pdus_cnt;

	/* custom statistics */

	uint32_t		sendpage_failures_cnt;

	uint32_t		discontiguous_hdr_cnt;

	uint32_t		eh_abort_cnt;

};

struct iscsi_session {

	/* iSCSI session-wide sequencing */

	uint32_t		cmdsn;

	uint32_t		exp_cmdsn;

	uint32_t		max_cmdsn;

	/* configuration */

	int			initial_r2t_en;

	int			max_r2t;

	int			imm_data_en;

	int			first_burst;

	int			max_burst;

	int			time2wait;

	int			time2retain;

	int			pdu_inorder_en;

	int			dataseq_inorder_en;

	int			erl;

	int			ifmarker_en;

	int			ofmarker_en;

	/* control data */

	struct Scsi_Host	*host;

	int			id;

	struct iscsi_conn	*leadconn;	/* leading connection */

	spinlock_t		lock;		/* protects session state, *

						 * sequence numbers,       *

						 * session resources:      *

						 * - cmdpool,		   *

						 * - mgmtpool,		   *

						 * - r2tpool		   */

	int			state;		/* session state           */

	struct list_head	item;

	void			*auth_client;

	int			conn_cnt;

	int			age;		/* counts session re-opens */

	struct list_head	connections;	/* list of connections */

	int			cmds_max;	/* size of cmds array */

	struct iscsi_cmd_task	**cmds;		/* Original Cmds arr */

	struct iscsi_queue	cmdpool;	/* PDU's pool */

	int			mgmtpool_max;	/* size of mgmt array */

	struct iscsi_mgmt_task	**mgmt_cmds;	/* Original mgmt arr */

	struct iscsi_queue	mgmtpool;	/* Mgmt PDU's pool */

};

struct iscsi_buf {

	struct scatterlist	sg;

	struct kvec		iov;

	unsigned int		sent;

};

struct iscsi_data_task {

	struct iscsi_data	hdr;			/* PDU */

	char			hdrext[sizeof(__u32)];	/* Header-Digest */

	struct list_head	item;			/* data queue item */

	struct iscsi_buf	digestbuf;		/* digest buffer */

	uint32_t		digest;			/* data digest */

};

#define ISCSI_DTASK_DEFAULT_MAX	ISCSI_SG_TABLESIZE * PAGE_SIZE / 512

struct iscsi_mgmt_task {

	struct iscsi_hdr	hdr;		/* mgmt. PDU */

	char			hdrext[sizeof(__u32)];	/* Header-Digest */

	char			*data;		/* mgmt payload */

	int			xmstate;	/* mgmt xmit progress */

	int			data_count;	/* counts data to be sent */

	struct iscsi_buf	headbuf;	/* header buffer */

	struct iscsi_buf	sendbuf;	/* in progress buffer */

	int			sent;

	uint32_t		itt;		/* this ITT */

};

struct iscsi_r2t_info {

	__be32			ttt;		/* copied from R2T */

	__be32			exp_statsn;	/* copied from R2T */

	uint32_t		data_length;	/* copied from R2T */

	uint32_t		data_offset;	/* copied from R2T */

	struct iscsi_buf	headbuf;	/* Data-Out Header Buffer */

	struct iscsi_buf	sendbuf;	/* Data-Out in progress buffer*/

	int			sent;		/* R2T sequence progress */

	int			data_count;	/* DATA-Out payload progress */

	struct scatterlist	*sg;		/* per-R2T SG list */

	int			solicit_datasn;

	struct iscsi_data_task   *dtask;        /* which data task */

};

struct iscsi_cmd_task {

	struct iscsi_cmd	hdr;			/* iSCSI PDU header */

	char			hdrext[4*sizeof(__u16)+	/* AHS */

				    sizeof(__u32)];	/* HeaderDigest */

	char			pad[ISCSI_PAD_LEN];

	int			itt;			/* this ITT */

	int			datasn;			/* DataSN */

	struct iscsi_buf	headbuf;		/* header buf (xmit) */

	struct iscsi_buf	sendbuf;		/* in progress buffer*/

	int			sent;

	struct scatterlist	*sg;			/* per-cmd SG list  */

	struct scatterlist	*bad_sg;		/* assert statement */

	int			sg_count;		/* SG's to process  */

	uint32_t		unsol_datasn;

	uint32_t		exp_r2tsn;

	int			xmstate;		/* xmit xtate machine */

	int			imm_count;		/* imm-data (bytes)   */

	int			unsol_count;		/* unsolicited (bytes)*/

	int			r2t_data_count;		/* R2T Data-Out bytes */

	int			data_count;		/* remaining Data-Out */

	int			pad_count;		/* padded bytes */

	struct scsi_cmnd	*sc;			/* associated SCSI cmd*/

	int			total_length;

	int			data_offset;

	struct iscsi_conn	*conn;			/* used connection    */

	struct iscsi_mgmt_task	*mtask;			/* tmf mtask in progr */

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

	struct iscsi_queue	r2tpool;

	struct kfifo		*r2tqueue;

	struct iscsi_r2t_info	**r2ts;

	struct list_head	dataqueue;		/* Data-Out dataqueue */

	mempool_t		*datapool;

	uint32_t		datadigest;		/* for recover digest */

	int			digest_count;

	uint32_t		immdigest;		/* for imm data */

	struct iscsi_buf	immbuf;			/* for imm data digest */

	struct iscsi_data_task   *dtask;		/* data task in progress*/

	int			digest_offset;		/* for partial buff digest */

};

#endif /* ISCSI_H */