1 /* SPDX-License-Identifier: GPL-2.0-only */
2 /*
3 * Copyright(c) 2007 Intel Corporation. All rights reserved.
4 *
5 * Maintained at www.Open-FCoE.org
6 */
7
8 #ifndef _FC_FRAME_H_
9 #define _FC_FRAME_H_
10
11 #include <linux/scatterlist.h>
12 #include <linux/skbuff.h>
13 #include <scsi/scsi_cmnd.h>
14
15 #include <scsi/fc/fc_fs.h>
16 #include <scsi/fc/fc_fcp.h>
17 #include <scsi/fc/fc_encaps.h>
18
19 #include <linux/if_ether.h>
20
21 /* some helpful macros */
22
23 #define ntohll(x) be64_to_cpu(x)
24 #define htonll(x) cpu_to_be64(x)
25
26 static inline u32 ntoh24(const u8 *p)
27 {
28 return (p[0] << 16) | (p[1] << 8) | p[2];
29 }
30
31 static inline void hton24(u8 *p, u32 v)
32 {
33 p[0] = (v >> 16) & 0xff;
34 p[1] = (v >> 8) & 0xff;
35 p[2] = v & 0xff;
36 }
37
38 /*
39 * The fc_frame interface is used to pass frame data between functions.
40 * The frame includes the data buffer, length, and SOF / EOF delimiter types.
41 * A pointer to the port structure of the receiving port is also includeded.
42 */
43
44 #define FC_FRAME_HEADROOM 32 /* headroom for VLAN + FCoE headers */
45 #define FC_FRAME_TAILROOM 8 /* trailer space for FCoE */
46
47 /* Max number of skb frags allowed, reserving one for fcoe_crc_eof page */
48 #define FC_FRAME_SG_LEN (MAX_SKB_FRAGS - 1)
49
50 #define fp_skb(fp) (&((fp)->skb))
51 #define fr_hdr(fp) ((fp)->skb.data)
52 #define fr_len(fp) ((fp)->skb.len)
53 #define fr_cb(fp) ((struct fcoe_rcv_info *)&((fp)->skb.cb[0]))
54 #define fr_dev(fp) (fr_cb(fp)->fr_dev)
55 #define fr_seq(fp) (fr_cb(fp)->fr_seq)
56 #define fr_sof(fp) (fr_cb(fp)->fr_sof)
57 #define fr_eof(fp) (fr_cb(fp)->fr_eof)
58 #define fr_flags(fp) (fr_cb(fp)->fr_flags)
59 #define fr_encaps(fp) (fr_cb(fp)->fr_encaps)
60 #define fr_max_payload(fp) (fr_cb(fp)->fr_max_payload)
61 #define fr_fsp(fp) (fr_cb(fp)->fr_fsp)
62 #define fr_crc(fp) (fr_cb(fp)->fr_crc)
63
64 struct fc_frame {
65 struct sk_buff skb;
66 };
67
68 struct fcoe_rcv_info {
69 struct fc_lport *fr_dev; /* transport layer private pointer */
70 struct fc_seq *fr_seq; /* for use with exchange manager */
71 struct fc_fcp_pkt *fr_fsp; /* for the corresponding fcp I/O */
72 u32 fr_crc;
73 u16 fr_max_payload; /* max FC payload */
74 u8 fr_sof; /* start of frame delimiter */
75 u8 fr_eof; /* end of frame delimiter */
76 u8 fr_flags; /* flags - see below */
77 u8 fr_encaps; /* LLD encapsulation info (e.g. FIP) */
78 u8 granted_mac[ETH_ALEN]; /* FCoE MAC address */
79 };
80
81
82 /*
83 * Get fc_frame pointer for an skb that's already been imported.
84 */
85 static inline struct fcoe_rcv_info *fcoe_dev_from_skb(const struct sk_buff *skb)
86 {
87 BUILD_BUG_ON(sizeof(struct fcoe_rcv_info) > sizeof(skb->cb));
88 return (struct fcoe_rcv_info *) skb->cb;
89 }
90
91 /*
92 * fr_flags.
93 */
94 #define FCPHF_CRC_UNCHECKED 0x01 /* CRC not computed, still appended */
95
96 /*
97 * Initialize a frame.
98 * We don't do a complete memset here for performance reasons.
99 * The caller must set fr_free, fr_hdr, fr_len, fr_sof, and fr_eof eventually.
100 */
101 static inline void fc_frame_init(struct fc_frame *fp)
102 {
103 fr_dev(fp) = NULL;
104 fr_seq(fp) = NULL;
105 fr_flags(fp) = 0;
106 fr_encaps(fp) = 0;
107 }
108
109 struct fc_frame *fc_frame_alloc_fill(struct fc_lport *, size_t payload_len);
110 struct fc_frame *_fc_frame_alloc(size_t payload_len);
111
112 /*
113 * Allocate fc_frame structure and buffer. Set the initial length to
114 * payload_size + sizeof (struct fc_frame_header).
115 */
116 static inline struct fc_frame *fc_frame_alloc(struct fc_lport *dev, size_t len)
117 {
118 struct fc_frame *fp;
119
120 /*
121 * Note: Since len will often be a constant multiple of 4,
122 * this check will usually be evaluated and eliminated at compile time.
123 */
124 if (len && len % 4)
125 fp = fc_frame_alloc_fill(dev, len);
126 else
127 fp = _fc_frame_alloc(len);
128 return fp;
129 }
130
131 /*
132 * Free the fc_frame structure and buffer.
133 */
134 static inline void fc_frame_free(struct fc_frame *fp)
135 {
136 kfree_skb(fp_skb(fp));
137 }
138
139 static inline int fc_frame_is_linear(struct fc_frame *fp)
140 {
141 return !skb_is_nonlinear(fp_skb(fp));
142 }
143
144 /*
145 * Get frame header from message in fc_frame structure.
146 * This version doesn't do a length check.
147 */
148 static inline
149 struct fc_frame_header *__fc_frame_header_get(const struct fc_frame *fp)
150 {
151 return (struct fc_frame_header *)fr_hdr(fp);
152 }
153
154 /*
155 * Get frame header from message in fc_frame structure.
156 * This hides a cast and provides a place to add some checking.
157 */
158 static inline
159 struct fc_frame_header *fc_frame_header_get(const struct fc_frame *fp)
160 {
161 WARN_ON(fr_len(fp) < sizeof(struct fc_frame_header));
162 return __fc_frame_header_get(fp);
163 }
164
165 /*
166 * Get source FC_ID (S_ID) from frame header in message.
167 */
168 static inline u32 fc_frame_sid(const struct fc_frame *fp)
169 {
170 return ntoh24(__fc_frame_header_get(fp)->fh_s_id);
171 }
172
173 /*
174 * Get destination FC_ID (D_ID) from frame header in message.
175 */
176 static inline u32 fc_frame_did(const struct fc_frame *fp)
177 {
178 return ntoh24(__fc_frame_header_get(fp)->fh_d_id);
179 }
180
181 /*
182 * Get frame payload from message in fc_frame structure.
183 * This hides a cast and provides a place to add some checking.
184 * The len parameter is the minimum length for the payload portion.
185 * Returns NULL if the frame is too short.
186 *
187 * This assumes the interesting part of the payload is in the first part
188 * of the buffer for received data. This may not be appropriate to use for
189 * buffers being transmitted.
190 */
191 static inline void *fc_frame_payload_get(const struct fc_frame *fp,
192 size_t len)
193 {
194 void *pp = NULL;
195
196 if (fr_len(fp) >= sizeof(struct fc_frame_header) + len)
197 pp = fc_frame_header_get(fp) + 1;
198 return pp;
199 }
200
201 /*
202 * Get frame payload opcode (first byte) from message in fc_frame structure.
203 * This hides a cast and provides a place to add some checking. Return 0
204 * if the frame has no payload.
205 */
206 static inline u8 fc_frame_payload_op(const struct fc_frame *fp)
207 {
208 u8 *cp;
209
210 cp = fc_frame_payload_get(fp, sizeof(u8));
211 if (!cp)
212 return 0;
213 return *cp;
214
215 }
216
217 /*
218 * Get FC class from frame.
219 */
220 static inline enum fc_class fc_frame_class(const struct fc_frame *fp)
221 {
222 return fc_sof_class(fr_sof(fp));
223 }
224
225 /*
226 * Check the CRC in a frame.
227 * The CRC immediately follows the last data item *AFTER* the length.
228 * The return value is zero if the CRC matches.
229 */
230 u32 fc_frame_crc_check(struct fc_frame *);
231
232 static inline u8 fc_frame_rctl(const struct fc_frame *fp)
233 {
234 return fc_frame_header_get(fp)->fh_r_ctl;
235 }
236
237 static inline bool fc_frame_is_cmd(const struct fc_frame *fp)
238 {
239 return fc_frame_rctl(fp) == FC_RCTL_DD_UNSOL_CMD;
240 }
241
242 /*
243 * Check for leaks.
244 * Print the frame header of any currently allocated frame, assuming there
245 * should be none at this point.
246 */
247 void fc_frame_leak_check(void);
248
249 static inline void __fc_fill_fc_hdr(struct fc_frame_header *fh,
250 enum fc_rctl r_ctl,
251 u32 did, u32 sid, enum fc_fh_type type,
252 u32 f_ctl, u32 parm_offset)
253 {
254 WARN_ON(r_ctl == 0);
255 fh->fh_r_ctl = r_ctl;
256 hton24(fh->fh_d_id, did);
257 hton24(fh->fh_s_id, sid);
258 fh->fh_type = type;
259 hton24(fh->fh_f_ctl, f_ctl);
260 fh->fh_cs_ctl = 0;
261 fh->fh_df_ctl = 0;
262 fh->fh_parm_offset = htonl(parm_offset);
263 }
264
265 /**
266 * fill FC header fields in specified fc_frame
267 */
268 static inline void fc_fill_fc_hdr(struct fc_frame *fp, enum fc_rctl r_ctl,
269 u32 did, u32 sid, enum fc_fh_type type,
270 u32 f_ctl, u32 parm_offset)
271 {
272 struct fc_frame_header *fh;
273
274 fh = fc_frame_header_get(fp);
275 __fc_fill_fc_hdr(fh, r_ctl, did, sid, type, f_ctl, parm_offset);
276 }
277
278
279 #endif /* _FC_FRAME_H_ */
280
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