summaryrefslogtreecommitdiffstats
path: root/drivers/scsi/iscsi_tcp.h
blob: 9badafe8820d68f122ddacd05ea856edb1ae764b (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
/*
 * 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_DEF_CMD_PER_LUN		32
#define ISCSI_MAX_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 mutex		xmitmutex;	/* 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 */
OpenPOWER on IntegriCloud