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 #endif /* _FC_FRAME_H_ */ 250