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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.org6 */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 26static inline u32 ntoh24(const u8 *p)27{28 return (p[0] << 16) | (p[1] << 8) | p[2];29}30 31static 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 64struct fc_frame {65 struct sk_buff skb;66};67 68struct 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 */85static 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 */101static 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 109struct fc_frame *fc_frame_alloc_fill(struct fc_lport *, size_t payload_len);110struct fc_frame *_fc_frame_alloc(size_t payload_len);111 112/*113 * Allocate fc_frame structure and buffer. Set the initial length to114 * payload_size + sizeof (struct fc_frame_header).115 */116static 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 else127 fp = _fc_frame_alloc(len);128 return fp;129}130 131/*132 * Free the fc_frame structure and buffer.133 */134static inline void fc_frame_free(struct fc_frame *fp)135{136 kfree_skb(fp_skb(fp));137}138 139static 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 */148static inline149struct 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 */158static inline159struct 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 */168static 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 */176static 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 part188 * of the buffer for received data. This may not be appropriate to use for189 * buffers being transmitted.190 */191static 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 0204 * if the frame has no payload.205 */206static 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 */220static 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 */230u32 fc_frame_crc_check(struct fc_frame *);231 232static inline u8 fc_frame_rctl(const struct fc_frame *fp)233{234 return fc_frame_header_get(fp)->fh_r_ctl;235}236 237static 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 there245 * should be none at this point.246 */247void fc_frame_leak_check(void);248 249static 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_frame267 */268static 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