aboutsummaryrefslogtreecommitdiffstats
path: root/include/scsi/fc_frame.h
blob: c35d2383cc2663a2bed346d8ea0aa78f227ffa6a (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
/*
 * Copyright(c) 2007 Intel Corporation. All rights reserved.
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms and conditions of the GNU General Public License,
 * version 2, as published by the Free Software Foundation.
 *
 * This program is distributed in the hope 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.
 *
 * You should have received a copy of the GNU General Public License along with
 * this program; if not, write to the Free Software Foundation, Inc.,
 * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Maintained at www.Open-FCoE.org
 */

#ifndef _FC_FRAME_H_
#define _FC_FRAME_H_

#include <linux/scatterlist.h>
#include <linux/skbuff.h>
#include <scsi/scsi_cmnd.h>

#include <scsi/fc/fc_fs.h>
#include <scsi/fc/fc_fcp.h>
#include <scsi/fc/fc_encaps.h>

/*
 * The fc_frame interface is used to pass frame data between functions.
 * The frame includes the data buffer, length, and SOF / EOF delimiter types.
 * A pointer to the port structure of the receiving port is also includeded.
 */

#define	FC_FRAME_HEADROOM	32	/* headroom for VLAN + FCoE headers */
#define	FC_FRAME_TAILROOM	8	/* trailer space for FCoE */

#define fp_skb(fp)	(&((fp)->skb))
#define fr_hdr(fp)	((fp)->skb.data)
#define fr_len(fp)	((fp)->skb.len)
#define fr_cb(fp)	((struct fcoe_rcv_info *)&((fp)->skb.cb[0]))
#define fr_dev(fp)	(fr_cb(fp)->fr_dev)
#define fr_seq(fp)	(fr_cb(fp)->fr_seq)
#define fr_sof(fp)	(fr_cb(fp)->fr_sof)
#define fr_eof(fp)	(fr_cb(fp)->fr_eof)
#define fr_flags(fp)	(fr_cb(fp)->fr_flags)
#define fr_max_payload(fp)	(fr_cb(fp)->fr_max_payload)
#define fr_fsp(fp)	(fr_cb(fp)->fr_fsp)
#define fr_crc(fp)	(fr_cb(fp)->fr_crc)

struct fc_frame {
	struct sk_buff skb;
};

struct fcoe_rcv_info {
	struct packet_type  *ptype;
	struct fc_lport	*fr_dev;	/* transport layer private pointer */
	struct fc_seq	*fr_seq;	/* for use with exchange manager */
	struct fc_fcp_pkt *fr_fsp;	/* for the corresponding fcp I/O */
	u32		fr_crc;
	u16		fr_max_payload;	/* max FC payload */
	enum fc_sof	fr_sof;		/* start of frame delimiter */
	enum fc_eof	fr_eof;		/* end of frame delimiter */
	u8		fr_flags;	/* flags - see below */
};


/*
 * Get fc_frame pointer for an skb that's already been imported.
 */
static inline struct fcoe_rcv_info *fcoe_dev_from_skb(const struct sk_buff *skb)
{
	BUILD_BUG_ON(sizeof(struct fcoe_rcv_info) > sizeof(skb->cb));
	return (struct fcoe_rcv_info *) skb->cb;
}

/*
 * fr_flags.
 */
#define	FCPHF_CRC_UNCHECKED	0x01	/* CRC not computed, still appended */

/*
 * Initialize a frame.
 * We don't do a complete memset here for performance reasons.
 * The caller must set fr_free, fr_hdr, fr_len, fr_sof, and fr_eof eventually.
 */
static inline void fc_frame_init(struct fc_frame *fp)
{
	fr_dev(fp) = NULL;
	fr_seq(fp) = NULL;
	fr_flags(fp) = 0;
}

struct fc_frame *fc_frame_alloc_fill(struct fc_lport *, size_t payload_len);

struct fc_frame *__fc_frame_alloc(size_t payload_len);

/*
 * Get frame for sending via port.
 */
static inline struct fc_frame *_fc_frame_alloc(struct fc_lport *dev,
					       size_t payload_len)
{
	return __fc_frame_alloc(payload_len);
}

/*
 * Allocate fc_frame structure and buffer.  Set the initial length to
 * payload_size + sizeof (struct fc_frame_header).
 */
static inline struct fc_frame *fc_frame_alloc(struct fc_lport *dev, size_t len)
{
	struct fc_frame *fp;

	/*
	 * Note: Since len will often be a constant multiple of 4,
	 * this check will usually be evaluated and eliminated at compile time.
	 */
	if ((len % 4) != 0)
		fp = fc_frame_alloc_fill(dev, len);
	else
		fp = _fc_frame_alloc(dev, len);
	return fp;
}

/*
 * Free the fc_frame structure and buffer.
 */
static inline void fc_frame_free(struct fc_frame *fp)
{
	kfree_skb(fp_skb(fp));
}

static inline int fc_frame_is_linear(struct fc_frame *fp)
{
	return !skb_is_nonlinear(fp_skb(fp));
}

/*
 * Get frame header from message in fc_frame structure.
 * This hides a cast and provides a place to add some checking.
 */
static inline
struct fc_frame_header *fc_frame_header_get(const struct fc_frame *fp)
{
	WARN_ON(fr_len(fp) < sizeof(struct fc_frame_header));
	return (struct fc_frame_header *) fr_hdr(fp);
}

/*
 * Get frame payload from message in fc_frame structure.
 * This hides a cast and provides a place to add some checking.
 * The len parameter is the minimum length for the payload portion.
 * Returns NULL if the frame is too short.
 *
 * This assumes the interesting part of the payload is in the first part
 * of the buffer for received data.  This may not be appropriate to use for
 * buffers being transmitted.
 */
static inline void *fc_frame_payload_get(const struct fc_frame *fp,
					 size_t len)
{
	void *pp = NULL;

	if (fr_len(fp) >= sizeof(struct fc_frame_header) + len)
		pp = fc_frame_header_get(fp) + 1;
	return pp;
}

/*
 * Get frame payload opcode (first byte) from message in fc_frame structure.
 * This hides a cast and provides a place to add some checking. Return 0
 * if the frame has no payload.
 */
static inline u8 fc_frame_payload_op(const struct fc_frame *fp)
{
	u8 *cp;

	cp = fc_frame_payload_get(fp, sizeof(u8));
	if (!cp)
		return 0;
	return *cp;

}

/*
 * Get FC class from frame.
 */
static inline enum fc_class fc_frame_class(const struct fc_frame *fp)
{
	return fc_sof_class(fr_sof(fp));
}

/*
 * Check the CRC in a frame.
 * The CRC immediately follows the last data item *AFTER* the length.
 * The return value is zero if the CRC matches.
 */
u32 fc_frame_crc_check(struct fc_frame *);

static inline u8 fc_frame_rctl(const struct fc_frame *fp)
{
	return fc_frame_header_get(fp)->fh_r_ctl;
}

static inline bool fc_frame_is_cmd(const struct fc_frame *fp)
{
	return fc_frame_rctl(fp) == FC_RCTL_DD_UNSOL_CMD;
}

/*
 * Check for leaks.
 * Print the frame header of any currently allocated frame, assuming there
 * should be none at this point.
 */
void fc_frame_leak_check(void);

#endif /* _FC_FRAME_H_ */