summaryrefslogtreecommitdiff
path: root/drivers/scsi/iscsi_tcp.h
blob: b039160ebafd81f4e1d801e594eff385970cbb6e (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
/*
 * iSCSI Initiator TCP Transport
 * Copyright (C) 2004 Dmitry Yusupov
 * Copyright (C) 2004 Alex Aizman
 * Copyright (C) 2005 - 2006 Mike Christie
 * Copyright (C) 2006 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 ISCSI_TCP_H
#define ISCSI_TCP_H

#include <scsi/libiscsi.h>

/* 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

/* xmit state machine */
#define XMSTATE_IDLE			0x0
#define XMSTATE_CMD_HDR_INIT		0x1
#define XMSTATE_CMD_HDR_XMIT		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_W_RESEND_PAD		0x400
#define XMSTATE_W_RESEND_DATA_DIGEST	0x800
#define XMSTATE_IMM_HDR_INIT		0x1000
#define XMSTATE_SOL_HDR_INIT		0x2000

#define ISCSI_PAD_LEN			4
#define ISCSI_SG_TABLESIZE		SG_ALL
#define ISCSI_TCP_MAX_CMD_LEN		16

struct crypto_hash;
struct socket;

/* 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			datalen;
	int			datadgst;
	char			zero_copy_hdr;
};

struct iscsi_tcp_conn {
	struct iscsi_conn	*iscsi_conn;
	struct socket		*sock;
	struct iscsi_hdr	hdr;		/* header placeholder */
	char			hdrext[4*sizeof(__u16) +
				    sizeof(__u32)];
	int			data_copied;
	int			stop_stage;	/* conn_stop() flag: *
						 * stop to recover,  *
						 * stop to terminate */
	/* iSCSI connection-wide sequencing */
	int			hdr_size;	/* PDU header size */

	/* control data */
	struct iscsi_tcp_recv	in;		/* TCP receive context */
	int			in_progress;	/* connection state machine */

	/* old values for socket callbacks */
	void			(*old_data_ready)(struct sock *, int);
	void			(*old_state_change)(struct sock *);
	void			(*old_write_space)(struct sock *);

	/* data and header digests */
	struct hash_desc	tx_hash;	/* CRC32C (Tx) */
	struct hash_desc	rx_hash;	/* CRC32C (Rx) */

	/* MIB custom statistics */
	uint32_t		sendpage_failures_cnt;
	uint32_t		discontiguous_hdr_cnt;

	ssize_t (*sendpage)(struct socket *, struct page *, int, size_t, int);
};

struct iscsi_buf {
	struct scatterlist	sg;
	unsigned int		sent;
	char			use_sendmsg;
};

struct iscsi_data_task {
	struct iscsi_data	hdr;			/* PDU */
	char			hdrext[sizeof(__u32)];	/* Header-Digest */
	struct iscsi_buf	digestbuf;		/* digest buffer */
	uint32_t		digest;			/* data digest */
};

struct iscsi_tcp_mgmt_task {
	struct iscsi_hdr	hdr;
	char			hdrext[sizeof(__u32)]; /* Header-Digest */
	int			xmstate;	/* mgmt xmit progress */
	struct iscsi_buf	headbuf;	/* header buffer */
	struct iscsi_buf	sendbuf;	/* in progress buffer */
	int			sent;
};

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_tcp_cmd_task {
	struct iscsi_cmd	hdr;
	char			hdrext[4*sizeof(__u16)+	/* AHS */
				    sizeof(__u32)];	/* HeaderDigest */
	char			pad[ISCSI_PAD_LEN];
	int			pad_count;		/* padded bytes */
	struct iscsi_buf	headbuf;		/* header buf (xmit) */
	struct iscsi_buf	sendbuf;		/* in progress buffer*/
	int			xmstate;		/* xmit xtate machine */
	int			sent;
	struct scatterlist	*sg;			/* per-cmd SG list  */
	struct scatterlist	*bad_sg;		/* assert statement */
	int			sg_count;		/* SG's to process  */
	uint32_t		exp_datasn;		/* expected target's R2TSN/DataSN */
	int			data_offset;
	struct iscsi_r2t_info	*r2t;			/* in progress R2T    */
	struct iscsi_queue	r2tpool;
	struct kfifo		*r2tqueue;
	struct iscsi_r2t_info	**r2ts;
	int			digest_count;
	uint32_t		immdigest;		/* for imm data */
	struct iscsi_buf	immbuf;			/* for imm data digest */
	struct iscsi_data_task	unsol_dtask;	/* unsol data task */
};

#endif /* ISCSI_H */