Robert Love | 42e9a92 | 2008-12-09 15:10:17 -0800 | [diff] [blame] | 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 | /* |
| 32 | * The fc_frame interface is used to pass frame data between functions. |
| 33 | * The frame includes the data buffer, length, and SOF / EOF delimiter types. |
| 34 | * A pointer to the port structure of the receiving port is also includeded. |
| 35 | */ |
| 36 | |
| 37 | #define FC_FRAME_HEADROOM 32 /* headroom for VLAN + FCoE headers */ |
| 38 | #define FC_FRAME_TAILROOM 8 /* trailer space for FCoE */ |
| 39 | |
Yi Zou | d37322a | 2009-10-21 16:27:58 -0700 | [diff] [blame^] | 40 | /* Max number of skb frags allowed, reserving one for fcoe_crc_eof page */ |
| 41 | #define FC_FRAME_SG_LEN (MAX_SKB_FRAGS - 1) |
| 42 | |
Robert Love | 42e9a92 | 2008-12-09 15:10:17 -0800 | [diff] [blame] | 43 | #define fp_skb(fp) (&((fp)->skb)) |
| 44 | #define fr_hdr(fp) ((fp)->skb.data) |
| 45 | #define fr_len(fp) ((fp)->skb.len) |
| 46 | #define fr_cb(fp) ((struct fcoe_rcv_info *)&((fp)->skb.cb[0])) |
| 47 | #define fr_dev(fp) (fr_cb(fp)->fr_dev) |
| 48 | #define fr_seq(fp) (fr_cb(fp)->fr_seq) |
| 49 | #define fr_sof(fp) (fr_cb(fp)->fr_sof) |
| 50 | #define fr_eof(fp) (fr_cb(fp)->fr_eof) |
| 51 | #define fr_flags(fp) (fr_cb(fp)->fr_flags) |
| 52 | #define fr_max_payload(fp) (fr_cb(fp)->fr_max_payload) |
Yi Zou | b277d2a | 2009-02-27 14:07:21 -0800 | [diff] [blame] | 53 | #define fr_fsp(fp) (fr_cb(fp)->fr_fsp) |
Robert Love | 42e9a92 | 2008-12-09 15:10:17 -0800 | [diff] [blame] | 54 | #define fr_crc(fp) (fr_cb(fp)->fr_crc) |
| 55 | |
| 56 | struct fc_frame { |
| 57 | struct sk_buff skb; |
| 58 | }; |
| 59 | |
| 60 | struct fcoe_rcv_info { |
| 61 | struct packet_type *ptype; |
| 62 | struct fc_lport *fr_dev; /* transport layer private pointer */ |
| 63 | struct fc_seq *fr_seq; /* for use with exchange manager */ |
Yi Zou | b277d2a | 2009-02-27 14:07:21 -0800 | [diff] [blame] | 64 | struct fc_fcp_pkt *fr_fsp; /* for the corresponding fcp I/O */ |
Robert Love | 42e9a92 | 2008-12-09 15:10:17 -0800 | [diff] [blame] | 65 | u32 fr_crc; |
| 66 | u16 fr_max_payload; /* max FC payload */ |
| 67 | enum fc_sof fr_sof; /* start of frame delimiter */ |
| 68 | enum fc_eof fr_eof; /* end of frame delimiter */ |
| 69 | u8 fr_flags; /* flags - see below */ |
| 70 | }; |
| 71 | |
| 72 | |
| 73 | /* |
| 74 | * Get fc_frame pointer for an skb that's already been imported. |
| 75 | */ |
| 76 | static inline struct fcoe_rcv_info *fcoe_dev_from_skb(const struct sk_buff *skb) |
| 77 | { |
| 78 | BUILD_BUG_ON(sizeof(struct fcoe_rcv_info) > sizeof(skb->cb)); |
| 79 | return (struct fcoe_rcv_info *) skb->cb; |
| 80 | } |
| 81 | |
| 82 | /* |
| 83 | * fr_flags. |
| 84 | */ |
| 85 | #define FCPHF_CRC_UNCHECKED 0x01 /* CRC not computed, still appended */ |
| 86 | |
| 87 | /* |
| 88 | * Initialize a frame. |
| 89 | * We don't do a complete memset here for performance reasons. |
| 90 | * The caller must set fr_free, fr_hdr, fr_len, fr_sof, and fr_eof eventually. |
| 91 | */ |
| 92 | static inline void fc_frame_init(struct fc_frame *fp) |
| 93 | { |
| 94 | fr_dev(fp) = NULL; |
| 95 | fr_seq(fp) = NULL; |
| 96 | fr_flags(fp) = 0; |
| 97 | } |
| 98 | |
| 99 | struct fc_frame *fc_frame_alloc_fill(struct fc_lport *, size_t payload_len); |
| 100 | |
| 101 | struct fc_frame *__fc_frame_alloc(size_t payload_len); |
| 102 | |
| 103 | /* |
| 104 | * Get frame for sending via port. |
| 105 | */ |
| 106 | static inline struct fc_frame *_fc_frame_alloc(struct fc_lport *dev, |
| 107 | size_t payload_len) |
| 108 | { |
| 109 | return __fc_frame_alloc(payload_len); |
| 110 | } |
| 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 % 4) != 0) |
| 125 | fp = fc_frame_alloc_fill(dev, len); |
| 126 | else |
| 127 | fp = _fc_frame_alloc(dev, 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 hides a cast and provides a place to add some checking. |
| 147 | */ |
| 148 | static inline |
| 149 | struct fc_frame_header *fc_frame_header_get(const struct fc_frame *fp) |
| 150 | { |
| 151 | WARN_ON(fr_len(fp) < sizeof(struct fc_frame_header)); |
| 152 | return (struct fc_frame_header *) fr_hdr(fp); |
| 153 | } |
| 154 | |
| 155 | /* |
| 156 | * Get frame payload from message in fc_frame structure. |
| 157 | * This hides a cast and provides a place to add some checking. |
| 158 | * The len parameter is the minimum length for the payload portion. |
| 159 | * Returns NULL if the frame is too short. |
| 160 | * |
| 161 | * This assumes the interesting part of the payload is in the first part |
| 162 | * of the buffer for received data. This may not be appropriate to use for |
| 163 | * buffers being transmitted. |
| 164 | */ |
| 165 | static inline void *fc_frame_payload_get(const struct fc_frame *fp, |
| 166 | size_t len) |
| 167 | { |
| 168 | void *pp = NULL; |
| 169 | |
| 170 | if (fr_len(fp) >= sizeof(struct fc_frame_header) + len) |
| 171 | pp = fc_frame_header_get(fp) + 1; |
| 172 | return pp; |
| 173 | } |
| 174 | |
| 175 | /* |
| 176 | * Get frame payload opcode (first byte) from message in fc_frame structure. |
| 177 | * This hides a cast and provides a place to add some checking. Return 0 |
| 178 | * if the frame has no payload. |
| 179 | */ |
| 180 | static inline u8 fc_frame_payload_op(const struct fc_frame *fp) |
| 181 | { |
| 182 | u8 *cp; |
| 183 | |
| 184 | cp = fc_frame_payload_get(fp, sizeof(u8)); |
| 185 | if (!cp) |
| 186 | return 0; |
| 187 | return *cp; |
| 188 | |
| 189 | } |
| 190 | |
| 191 | /* |
| 192 | * Get FC class from frame. |
| 193 | */ |
| 194 | static inline enum fc_class fc_frame_class(const struct fc_frame *fp) |
| 195 | { |
| 196 | return fc_sof_class(fr_sof(fp)); |
| 197 | } |
| 198 | |
| 199 | /* |
| 200 | * Check the CRC in a frame. |
| 201 | * The CRC immediately follows the last data item *AFTER* the length. |
| 202 | * The return value is zero if the CRC matches. |
| 203 | */ |
| 204 | u32 fc_frame_crc_check(struct fc_frame *); |
| 205 | |
| 206 | static inline u8 fc_frame_rctl(const struct fc_frame *fp) |
| 207 | { |
| 208 | return fc_frame_header_get(fp)->fh_r_ctl; |
| 209 | } |
| 210 | |
| 211 | static inline bool fc_frame_is_cmd(const struct fc_frame *fp) |
| 212 | { |
| 213 | return fc_frame_rctl(fp) == FC_RCTL_DD_UNSOL_CMD; |
| 214 | } |
| 215 | |
Robert Love | 42e9a92 | 2008-12-09 15:10:17 -0800 | [diff] [blame] | 216 | /* |
| 217 | * Check for leaks. |
| 218 | * Print the frame header of any currently allocated frame, assuming there |
| 219 | * should be none at this point. |
| 220 | */ |
| 221 | void fc_frame_leak_check(void); |
| 222 | |
| 223 | #endif /* _FC_FRAME_H_ */ |