aboutsummaryrefslogtreecommitdiffstats
path: root/include/scsi/libiscsi_tcp.h
blob: 215469a9b8014c0925f675c77a8e926a1d83c788 (plain) (blame)
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
/*
 * 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		padbuf[ISCSI_PAD_LEN];
	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;
	bool			atomic_mapped;

	iscsi_segment_done_fn_t	*done;
};

/* Socket connection receive 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_tcp_conn *tcp_conn,
				  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 int iscsi_tcp_set_max_r2t(struct iscsi_conn *conn, char *buf);
extern void iscsi_tcp_conn_get_stats(struct iscsi_cls_conn *cls_conn,
				     struct iscsi_stats *stats);
#endif /* LIBISCSI_TCP_H */