blob: c35d2383cc2663a2bed346d8ea0aa78f227ffa6a [file] [log] [blame]
Robert Love42e9a922008-12-09 15:10:17 -08001/*
2 * Copyright(c) 2007 Intel Corporation. All rights reserved.
3 *
4 * This program is free software; you can redistribute it and/or modify it
5 * under the terms and conditions of the GNU General Public License,
6 * version 2, as published by the Free Software Foundation.
7 *
8 * This program is distributed in the hope it will be useful, but WITHOUT
9 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
10 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
11 * more details.
12 *
13 * You should have received a copy of the GNU General Public License along with
14 * this program; if not, write to the Free Software Foundation, Inc.,
15 * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
16 *
17 * Maintained at www.Open-FCoE.org
18 */
19
20#ifndef _FC_FRAME_H_
21#define _FC_FRAME_H_
22
23#include <linux/scatterlist.h>
24#include <linux/skbuff.h>
25#include <scsi/scsi_cmnd.h>
26
27#include <scsi/fc/fc_fs.h>
28#include <scsi/fc/fc_fcp.h>
29#include <scsi/fc/fc_encaps.h>
30
31/*
32 * The fc_frame interface is used to pass frame data between functions.
33 * The frame includes the data buffer, length, and SOF / EOF delimiter types.
34 * A pointer to the port structure of the receiving port is also includeded.
35 */
36
37#define FC_FRAME_HEADROOM 32 /* headroom for VLAN + FCoE headers */
38#define FC_FRAME_TAILROOM 8 /* trailer space for FCoE */
39
Robert Love42e9a922008-12-09 15:10:17 -080040#define fp_skb(fp) (&((fp)->skb))
41#define fr_hdr(fp) ((fp)->skb.data)
42#define fr_len(fp) ((fp)->skb.len)
43#define fr_cb(fp) ((struct fcoe_rcv_info *)&((fp)->skb.cb[0]))
44#define fr_dev(fp) (fr_cb(fp)->fr_dev)
45#define fr_seq(fp) (fr_cb(fp)->fr_seq)
46#define fr_sof(fp) (fr_cb(fp)->fr_sof)
47#define fr_eof(fp) (fr_cb(fp)->fr_eof)
48#define fr_flags(fp) (fr_cb(fp)->fr_flags)
49#define fr_max_payload(fp) (fr_cb(fp)->fr_max_payload)
Yi Zoub277d2a2009-02-27 14:07:21 -080050#define fr_fsp(fp) (fr_cb(fp)->fr_fsp)
Robert Love42e9a922008-12-09 15:10:17 -080051#define fr_crc(fp) (fr_cb(fp)->fr_crc)
52
53struct fc_frame {
54 struct sk_buff skb;
55};
56
57struct fcoe_rcv_info {
58 struct packet_type *ptype;
59 struct fc_lport *fr_dev; /* transport layer private pointer */
60 struct fc_seq *fr_seq; /* for use with exchange manager */
Yi Zoub277d2a2009-02-27 14:07:21 -080061 struct fc_fcp_pkt *fr_fsp; /* for the corresponding fcp I/O */
Robert Love42e9a922008-12-09 15:10:17 -080062 u32 fr_crc;
63 u16 fr_max_payload; /* max FC payload */
64 enum fc_sof fr_sof; /* start of frame delimiter */
65 enum fc_eof fr_eof; /* end of frame delimiter */
66 u8 fr_flags; /* flags - see below */
67};
68
69
70/*
71 * Get fc_frame pointer for an skb that's already been imported.
72 */
73static inline struct fcoe_rcv_info *fcoe_dev_from_skb(const struct sk_buff *skb)
74{
75 BUILD_BUG_ON(sizeof(struct fcoe_rcv_info) > sizeof(skb->cb));
76 return (struct fcoe_rcv_info *) skb->cb;
77}
78
79/*
80 * fr_flags.
81 */
82#define FCPHF_CRC_UNCHECKED 0x01 /* CRC not computed, still appended */
83
84/*
85 * Initialize a frame.
86 * We don't do a complete memset here for performance reasons.
87 * The caller must set fr_free, fr_hdr, fr_len, fr_sof, and fr_eof eventually.
88 */
89static inline void fc_frame_init(struct fc_frame *fp)
90{
91 fr_dev(fp) = NULL;
92 fr_seq(fp) = NULL;
93 fr_flags(fp) = 0;
94}
95
96struct fc_frame *fc_frame_alloc_fill(struct fc_lport *, size_t payload_len);
97
98struct fc_frame *__fc_frame_alloc(size_t payload_len);
99
100/*
101 * Get frame for sending via port.
102 */
103static inline struct fc_frame *_fc_frame_alloc(struct fc_lport *dev,
104 size_t payload_len)
105{
106 return __fc_frame_alloc(payload_len);
107}
108
109/*
110 * Allocate fc_frame structure and buffer. Set the initial length to
111 * payload_size + sizeof (struct fc_frame_header).
112 */
113static inline struct fc_frame *fc_frame_alloc(struct fc_lport *dev, size_t len)
114{
115 struct fc_frame *fp;
116
117 /*
118 * Note: Since len will often be a constant multiple of 4,
119 * this check will usually be evaluated and eliminated at compile time.
120 */
121 if ((len % 4) != 0)
122 fp = fc_frame_alloc_fill(dev, len);
123 else
124 fp = _fc_frame_alloc(dev, len);
125 return fp;
126}
127
128/*
129 * Free the fc_frame structure and buffer.
130 */
131static inline void fc_frame_free(struct fc_frame *fp)
132{
133 kfree_skb(fp_skb(fp));
134}
135
136static inline int fc_frame_is_linear(struct fc_frame *fp)
137{
138 return !skb_is_nonlinear(fp_skb(fp));
139}
140
141/*
142 * Get frame header from message in fc_frame structure.
143 * This hides a cast and provides a place to add some checking.
144 */
145static inline
146struct fc_frame_header *fc_frame_header_get(const struct fc_frame *fp)
147{
148 WARN_ON(fr_len(fp) < sizeof(struct fc_frame_header));
149 return (struct fc_frame_header *) fr_hdr(fp);
150}
151
152/*
153 * Get frame payload from message in fc_frame structure.
154 * This hides a cast and provides a place to add some checking.
155 * The len parameter is the minimum length for the payload portion.
156 * Returns NULL if the frame is too short.
157 *
158 * This assumes the interesting part of the payload is in the first part
159 * of the buffer for received data. This may not be appropriate to use for
160 * buffers being transmitted.
161 */
162static inline void *fc_frame_payload_get(const struct fc_frame *fp,
163 size_t len)
164{
165 void *pp = NULL;
166
167 if (fr_len(fp) >= sizeof(struct fc_frame_header) + len)
168 pp = fc_frame_header_get(fp) + 1;
169 return pp;
170}
171
172/*
173 * Get frame payload opcode (first byte) from message in fc_frame structure.
174 * This hides a cast and provides a place to add some checking. Return 0
175 * if the frame has no payload.
176 */
177static inline u8 fc_frame_payload_op(const struct fc_frame *fp)
178{
179 u8 *cp;
180
181 cp = fc_frame_payload_get(fp, sizeof(u8));
182 if (!cp)
183 return 0;
184 return *cp;
185
186}
187
188/*
189 * Get FC class from frame.
190 */
191static inline enum fc_class fc_frame_class(const struct fc_frame *fp)
192{
193 return fc_sof_class(fr_sof(fp));
194}
195
196/*
197 * Check the CRC in a frame.
198 * The CRC immediately follows the last data item *AFTER* the length.
199 * The return value is zero if the CRC matches.
200 */
201u32 fc_frame_crc_check(struct fc_frame *);
202
203static inline u8 fc_frame_rctl(const struct fc_frame *fp)
204{
205 return fc_frame_header_get(fp)->fh_r_ctl;
206}
207
208static inline bool fc_frame_is_cmd(const struct fc_frame *fp)
209{
210 return fc_frame_rctl(fp) == FC_RCTL_DD_UNSOL_CMD;
211}
212
Robert Love42e9a922008-12-09 15:10:17 -0800213/*
214 * Check for leaks.
215 * Print the frame header of any currently allocated frame, assuming there
216 * should be none at this point.
217 */
218void fc_frame_leak_check(void);
219
220#endif /* _FC_FRAME_H_ */