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42e9a92f RL |
1 | /* |
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 | ||
40 | /* | |
41 | * Information about an individual fibre channel frame received or to be sent. | |
42 | * The buffer may be in up to 4 additional non-contiguous sections, | |
43 | * but the linear section must hold the frame header. | |
44 | */ | |
45 | #define FC_FRAME_SG_LEN 4 /* scatter/gather list maximum length */ | |
46 | ||
47 | #define fp_skb(fp) (&((fp)->skb)) | |
48 | #define fr_hdr(fp) ((fp)->skb.data) | |
49 | #define fr_len(fp) ((fp)->skb.len) | |
50 | #define fr_cb(fp) ((struct fcoe_rcv_info *)&((fp)->skb.cb[0])) | |
51 | #define fr_dev(fp) (fr_cb(fp)->fr_dev) | |
52 | #define fr_seq(fp) (fr_cb(fp)->fr_seq) | |
53 | #define fr_sof(fp) (fr_cb(fp)->fr_sof) | |
54 | #define fr_eof(fp) (fr_cb(fp)->fr_eof) | |
55 | #define fr_flags(fp) (fr_cb(fp)->fr_flags) | |
56 | #define fr_max_payload(fp) (fr_cb(fp)->fr_max_payload) | |
b277d2aa | 57 | #define fr_fsp(fp) (fr_cb(fp)->fr_fsp) |
42e9a92f RL |
58 | #define fr_crc(fp) (fr_cb(fp)->fr_crc) |
59 | ||
60 | struct fc_frame { | |
61 | struct sk_buff skb; | |
62 | }; | |
63 | ||
64 | struct fcoe_rcv_info { | |
65 | struct packet_type *ptype; | |
66 | struct fc_lport *fr_dev; /* transport layer private pointer */ | |
67 | struct fc_seq *fr_seq; /* for use with exchange manager */ | |
b277d2aa | 68 | struct fc_fcp_pkt *fr_fsp; /* for the corresponding fcp I/O */ |
42e9a92f RL |
69 | u32 fr_crc; |
70 | u16 fr_max_payload; /* max FC payload */ | |
71 | enum fc_sof fr_sof; /* start of frame delimiter */ | |
72 | enum fc_eof fr_eof; /* end of frame delimiter */ | |
73 | u8 fr_flags; /* flags - see below */ | |
74 | }; | |
75 | ||
76 | ||
77 | /* | |
78 | * Get fc_frame pointer for an skb that's already been imported. | |
79 | */ | |
80 | static inline struct fcoe_rcv_info *fcoe_dev_from_skb(const struct sk_buff *skb) | |
81 | { | |
82 | BUILD_BUG_ON(sizeof(struct fcoe_rcv_info) > sizeof(skb->cb)); | |
83 | return (struct fcoe_rcv_info *) skb->cb; | |
84 | } | |
85 | ||
86 | /* | |
87 | * fr_flags. | |
88 | */ | |
89 | #define FCPHF_CRC_UNCHECKED 0x01 /* CRC not computed, still appended */ | |
90 | ||
91 | /* | |
92 | * Initialize a frame. | |
93 | * We don't do a complete memset here for performance reasons. | |
94 | * The caller must set fr_free, fr_hdr, fr_len, fr_sof, and fr_eof eventually. | |
95 | */ | |
96 | static inline void fc_frame_init(struct fc_frame *fp) | |
97 | { | |
98 | fr_dev(fp) = NULL; | |
99 | fr_seq(fp) = NULL; | |
100 | fr_flags(fp) = 0; | |
101 | } | |
102 | ||
103 | struct fc_frame *fc_frame_alloc_fill(struct fc_lport *, size_t payload_len); | |
104 | ||
105 | struct fc_frame *__fc_frame_alloc(size_t payload_len); | |
106 | ||
107 | /* | |
108 | * Get frame for sending via port. | |
109 | */ | |
110 | static inline struct fc_frame *_fc_frame_alloc(struct fc_lport *dev, | |
111 | size_t payload_len) | |
112 | { | |
113 | return __fc_frame_alloc(payload_len); | |
114 | } | |
115 | ||
116 | /* | |
117 | * Allocate fc_frame structure and buffer. Set the initial length to | |
118 | * payload_size + sizeof (struct fc_frame_header). | |
119 | */ | |
120 | static inline struct fc_frame *fc_frame_alloc(struct fc_lport *dev, size_t len) | |
121 | { | |
122 | struct fc_frame *fp; | |
123 | ||
124 | /* | |
125 | * Note: Since len will often be a constant multiple of 4, | |
126 | * this check will usually be evaluated and eliminated at compile time. | |
127 | */ | |
128 | if ((len % 4) != 0) | |
129 | fp = fc_frame_alloc_fill(dev, len); | |
130 | else | |
131 | fp = _fc_frame_alloc(dev, len); | |
132 | return fp; | |
133 | } | |
134 | ||
135 | /* | |
136 | * Free the fc_frame structure and buffer. | |
137 | */ | |
138 | static inline void fc_frame_free(struct fc_frame *fp) | |
139 | { | |
140 | kfree_skb(fp_skb(fp)); | |
141 | } | |
142 | ||
143 | static inline int fc_frame_is_linear(struct fc_frame *fp) | |
144 | { | |
145 | return !skb_is_nonlinear(fp_skb(fp)); | |
146 | } | |
147 | ||
148 | /* | |
149 | * Get frame header from message in fc_frame structure. | |
150 | * This hides a cast and provides a place to add some checking. | |
151 | */ | |
152 | static inline | |
153 | struct fc_frame_header *fc_frame_header_get(const struct fc_frame *fp) | |
154 | { | |
155 | WARN_ON(fr_len(fp) < sizeof(struct fc_frame_header)); | |
156 | return (struct fc_frame_header *) fr_hdr(fp); | |
157 | } | |
158 | ||
159 | /* | |
160 | * Get frame payload from message in fc_frame structure. | |
161 | * This hides a cast and provides a place to add some checking. | |
162 | * The len parameter is the minimum length for the payload portion. | |
163 | * Returns NULL if the frame is too short. | |
164 | * | |
165 | * This assumes the interesting part of the payload is in the first part | |
166 | * of the buffer for received data. This may not be appropriate to use for | |
167 | * buffers being transmitted. | |
168 | */ | |
169 | static inline void *fc_frame_payload_get(const struct fc_frame *fp, | |
170 | size_t len) | |
171 | { | |
172 | void *pp = NULL; | |
173 | ||
174 | if (fr_len(fp) >= sizeof(struct fc_frame_header) + len) | |
175 | pp = fc_frame_header_get(fp) + 1; | |
176 | return pp; | |
177 | } | |
178 | ||
179 | /* | |
180 | * Get frame payload opcode (first byte) from message in fc_frame structure. | |
181 | * This hides a cast and provides a place to add some checking. Return 0 | |
182 | * if the frame has no payload. | |
183 | */ | |
184 | static inline u8 fc_frame_payload_op(const struct fc_frame *fp) | |
185 | { | |
186 | u8 *cp; | |
187 | ||
188 | cp = fc_frame_payload_get(fp, sizeof(u8)); | |
189 | if (!cp) | |
190 | return 0; | |
191 | return *cp; | |
192 | ||
193 | } | |
194 | ||
195 | /* | |
196 | * Get FC class from frame. | |
197 | */ | |
198 | static inline enum fc_class fc_frame_class(const struct fc_frame *fp) | |
199 | { | |
200 | return fc_sof_class(fr_sof(fp)); | |
201 | } | |
202 | ||
203 | /* | |
204 | * Check the CRC in a frame. | |
205 | * The CRC immediately follows the last data item *AFTER* the length. | |
206 | * The return value is zero if the CRC matches. | |
207 | */ | |
208 | u32 fc_frame_crc_check(struct fc_frame *); | |
209 | ||
210 | static inline u8 fc_frame_rctl(const struct fc_frame *fp) | |
211 | { | |
212 | return fc_frame_header_get(fp)->fh_r_ctl; | |
213 | } | |
214 | ||
215 | static inline bool fc_frame_is_cmd(const struct fc_frame *fp) | |
216 | { | |
217 | return fc_frame_rctl(fp) == FC_RCTL_DD_UNSOL_CMD; | |
218 | } | |
219 | ||
42e9a92f RL |
220 | /* |
221 | * Check for leaks. | |
222 | * Print the frame header of any currently allocated frame, assuming there | |
223 | * should be none at this point. | |
224 | */ | |
225 | void fc_frame_leak_check(void); | |
226 | ||
227 | #endif /* _FC_FRAME_H_ */ |