aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/scsi/iscsi_tcp.h
blob: ed0b991d1e720b50e25897ac74642ce7c5530375 (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
/*
 * 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>

struct crypto_hash;
struct socket;
struct iscsi_tcp_conn;
struct iscsi_segment;

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;
};

/* Socket connection send helper */
struct iscsi_tcp_send {
	struct iscsi_hdr	*hdr;
	struct iscsi_segment	segment;
	struct iscsi_segment	data_segment;
};

struct iscsi_tcp_conn {
	struct iscsi_conn	*iscsi_conn;
	struct socket		*sock;
	int			stop_stage;	/* conn_stop() flag: *
						 * stop to recover,  *
						 * stop to terminate */
	/* control data */
	struct iscsi_tcp_recv	in;		/* TCP receive context */
	struct iscsi_tcp_send	out;		/* TCP send context */

	/* 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;

	int			error;

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

struct iscsi_data_task {
	struct iscsi_data	hdr;			/* PDU */
	char			hdrext[ISCSI_DIGEST_SIZE];/* Header-Digest */
};

struct iscsi_tcp_mgmt_task {
	struct iscsi_hdr	hdr;
	char			hdrext[ISCSI_DIGEST_SIZE]; /* Header-Digest */
};

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 */
	int			sent;		/* R2T sequence progress */
	int			data_count;	/* DATA-Out payload progress */
	int			solicit_datasn;
	struct iscsi_data_task	dtask;		/* Data-Out header buf */
};

struct iscsi_tcp_cmd_task {
	struct iscsi_hdr_buff {
		struct iscsi_cmd	cmd_hdr;
		char			hdrextbuf[ISCSI_MAX_AHS_SIZE +
		                                  ISCSI_DIGEST_SIZE];
	} hdr;

	int			sent;
	uint32_t		exp_datasn;	/* expected target's R2TSN/DataSN */
	int			data_offset;
	struct iscsi_r2t_info	*r2t;		/* in progress R2T    */
	struct iscsi_pool	r2tpool;
	struct kfifo		*r2tqueue;
	struct iscsi_data_task	unsol_dtask;	/* Data-Out header buf */
};

#endif /* ISCSI_H */