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