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 #ifndef _FC_ENCAPS_H_ 8 #define _FC_ENCAPS_H_ 9 10 /* 11 * Protocol definitions from RFC 3643 - Fibre Channel Frame Encapsulation. 12 * 13 * Note: The frame length field is the number of 32-bit words in 14 * the encapsulation including the fcip_encaps_header, CRC and EOF words. 15 * The minimum frame length value in bytes is (32 + 24 + 4 + 4) * 4 = 64. 16 * The maximum frame length value in bytes is (32 + 24 + 2112 + 4 + 4) = 2172. 17 */ 18 #define FC_ENCAPS_MIN_FRAME_LEN 64 /* min frame len (bytes) (see above) */ 19 #define FC_ENCAPS_MAX_FRAME_LEN (FC_ENCAPS_MIN_FRAME_LEN + FC_MAX_PAYLOAD) 20 21 #define FC_ENCAPS_VER 1 /* current version number */ 22 23 struct fc_encaps_hdr { 24 __u8 fc_proto; /* protocol number */ 25 __u8 fc_ver; /* version of encapsulation */ 26 __u8 fc_proto_n; /* ones complement of protocol */ 27 __u8 fc_ver_n; /* ones complement of version */ 28 29 unsigned char fc_proto_data[8]; /* protocol specific data */ 30 31 __be16 fc_len_flags; /* 10-bit length/4 w/ 6 flag bits */ 32 __be16 fc_len_flags_n; /* ones complement of length / flags */ 33 34 /* 35 * Offset 0x10 36 */ 37 __be32 fc_time[2]; /* time stamp: seconds and fraction */ 38 __be32 fc_crc; /* CRC */ 39 __be32 fc_sof; /* start of frame (see FC_SOF below) */ 40 41 /* 0x20 - FC frame content followed by EOF word */ 42 }; 43 44 #define FCIP_ENCAPS_HDR_LEN 0x20 /* expected length for asserts */ 45 46 /* 47 * Macro's for making redundant copies of EOF and SOF. 48 */ 49 #define FC_XY(x, y) ((((x) & 0xff) << 8) | ((y) & 0xff)) 50 #define FC_XYXY(x, y) ((FCIP_XY(x, y) << 16) | FCIP_XY(x, y)) 51 #define FC_XYNN(x, y) (FCIP_XYXY(x, y) ^ 0xffff) 52 53 #define FC_SOF_ENCODE(n) FC_XYNN(n, n) 54 #define FC_EOF_ENCODE(n) FC_XYNN(n, n) 55 56 /* 57 * SOF / EOF bytes. 58 */ 59 enum fc_sof { 60 FC_SOF_F = 0x28, /* fabric */ 61 FC_SOF_I4 = 0x29, /* initiate class 4 */ 62 FC_SOF_I2 = 0x2d, /* initiate class 2 */ 63 FC_SOF_I3 = 0x2e, /* initiate class 3 */ 64 FC_SOF_N4 = 0x31, /* normal class 4 */ 65 FC_SOF_N2 = 0x35, /* normal class 2 */ 66 FC_SOF_N3 = 0x36, /* normal class 3 */ 67 FC_SOF_C4 = 0x39, /* activate class 4 */ 68 } __attribute__((packed)); 69 70 enum fc_eof { 71 FC_EOF_N = 0x41, /* normal (not last frame of seq) */ 72 FC_EOF_T = 0x42, /* terminate (last frame of sequence) */ 73 FC_EOF_RT = 0x44, 74 FC_EOF_DT = 0x46, /* disconnect-terminate class-1 */ 75 FC_EOF_NI = 0x49, /* normal-invalid */ 76 FC_EOF_DTI = 0x4e, /* disconnect-terminate-invalid */ 77 FC_EOF_RTI = 0x4f, 78 FC_EOF_A = 0x50, /* abort */ 79 } __attribute__((packed)); 80 81 #define FC_SOF_CLASS_MASK 0x06 /* mask for class of service in SOF */ 82 83 /* 84 * Define classes in terms of the SOF code (initial). 85 */ 86 enum fc_class { 87 FC_CLASS_NONE = 0, /* software value indicating no class */ 88 FC_CLASS_2 = FC_SOF_I2, 89 FC_CLASS_3 = FC_SOF_I3, 90 FC_CLASS_4 = FC_SOF_I4, 91 FC_CLASS_F = FC_SOF_F, 92 }; 93 94 /* 95 * Determine whether SOF code indicates the need for a BLS ACK. 96 */ 97 static inline int fc_sof_needs_ack(enum fc_sof sof) 98 { 99 return (~sof) & 0x02; /* true for class 1, 2, 4, 6, or F */ 100 } 101 102 /* 103 * Given an fc_class, return the normal (non-initial) SOF value. 104 */ 105 static inline enum fc_sof fc_sof_normal(enum fc_class class) 106 { 107 return class + FC_SOF_N3 - FC_SOF_I3; /* diff is always 8 */ 108 } 109 110 /* 111 * Compute class from SOF value. 112 */ 113 static inline enum fc_class fc_sof_class(enum fc_sof sof) 114 { 115 return (sof & 0x7) | FC_SOF_F; 116 } 117 118 /* 119 * Determine whether SOF is for the initial frame of a sequence. 120 */ 121 static inline int fc_sof_is_init(enum fc_sof sof) 122 { 123 return sof < 0x30; 124 } 125 126 #endif /* _FC_ENCAPS_H_ */ 127