/*
* Copyright(c) 2007 Intel Corporation. All rights reserved.
*
* This program is free software; you can redistribute it and/or modify it
* under the terms and conditions of the GNU General Public License,
* version 2, as published by the Free Software Foundation.
*
* This program is distributed in the hope it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
* more details.
*
* You should have received a copy of the GNU General Public License along with
* this program; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
*
* Maintained at www.Open-FCoE.org
*/
#ifndef _FC_FRAME_H_
#define _FC_FRAME_H_
#include <linux/scatterlist.h>
#include <linux/skbuff.h>
#include <scsi/scsi_cmnd.h>
#include <scsi/fc/fc_fs.h>
#include <scsi/fc/fc_fcp.h>
#include <scsi/fc/fc_encaps.h>
#include <linux/if_ether.h>
/*
* The fc_frame interface is used to pass frame data between functions.
* The frame includes the data buffer, length, and SOF / EOF delimiter types.
* A pointer to the port structure of the receiving port is also includeded.
*/
#define FC_FRAME_HEADROOM 32 /* headroom for VLAN + FCoE headers */
#define FC_FRAME_TAILROOM 8 /* trailer space for FCoE */
/* Max number of skb frags allowed, reserving one for fcoe_crc_eof page */
#define FC_FRAME_SG_LEN (MAX_SKB_FRAGS - 1)
#define fp_skb(fp) (&((fp)->skb))
#define fr_hdr(fp) ((fp)->skb.data)
#define fr_len(fp) ((fp)->skb.len)
#define fr_cb(fp) ((struct fcoe_rcv_info *)&((fp)->skb.cb[0]))
#define fr_dev(fp) (fr_cb(fp)->fr_dev)
#define fr_seq(fp) (fr_cb(fp)->fr_seq)
#define fr_sof(fp) (fr_cb(fp)->fr_sof)
#define fr_eof(fp) (fr_cb(fp)->fr_eof)
#define fr_flags(fp) (fr_cb(fp)->fr_flags)
#define fr_max_payload(fp) (fr_cb(fp)->fr_max_payload)
#define fr_fsp(fp) (fr_cb(fp)->fr_fsp)
#define fr_crc(fp) (fr_cb(fp)->fr_crc)
struct fc_frame {
struct sk_buff skb;
};
struct fcoe_rcv_info {
struct packet_type *ptype;
struct fc_lport *fr_dev; /* transport layer private pointer */
struct fc_seq *fr_seq; /* for use with exchange manager */
struct fc_fcp_pkt *fr_fsp; /* for the corresponding fcp I/O */
u32 fr_crc;
u16 fr_max_payload; /* max FC payload */
enum fc_sof fr_sof; /* start of frame delimiter */
enum fc_eof fr_eof; /* end of frame delimiter */
u8 fr_flags; /* flags - see below */
u8 granted_mac[ETH_ALEN]; /* FCoE MAC address */
};
/*
* Get fc_frame pointer for an skb that's already been imported.
*/
static inline struct fcoe_rcv_info *fcoe_dev_from_skb(const struct sk_buff *skb)
{
BUILD_BUG_ON(sizeof(struct fcoe_rcv_info) > sizeof(skb->cb));
return (struct fcoe_rcv_info *) skb->cb;
}
/*
* fr_flags.
*/
#define FCPHF_CRC_UNCHECKED 0x01 /* CRC not computed, still appended */
/*
* Initialize a frame.
* We don't do a complete memset here for performance reasons.
* The caller must set fr_free, fr_hdr, fr_len, fr_sof, and fr_eof eventually.
*/
static inline void fc_frame_init(struct fc_frame *fp)
{
fr_dev(fp) = NULL;
fr_seq(fp) = NULL;
fr_flags(fp) = 0;
}
struct fc_frame *fc_frame_alloc_fill(struct fc_lport *, size_t payload_len);
struct fc_frame *__fc_frame_alloc(size_t payload_len);
/*
* Get frame for sending via port.
*/
static inline struct fc_frame *_fc_frame_alloc(struct fc_lport *dev,
size_t payload_len)
{
return __fc_frame_alloc(payload_len);
}
/*
* Allocate fc_frame structure and buffer. Set the initial length to
* payload_size + sizeof (struct fc_frame_header).
*/
static inline struct fc_frame *fc_frame_alloc(struct fc_lport *dev, size_t len)
{
struct fc_frame *fp;
/*
* Note: Since len will often be a constant multiple of 4,
* this check will usually be evaluated and eliminated at compile time.
*/
if ((len % 4) != 0)
fp = fc_frame_alloc_fill(dev, len);
else
fp = _fc_frame_alloc(dev, len);
return fp;
}
/*
* Free the fc_frame structure and buffer.
*/
static inline void fc_frame_free(struct fc_frame *fp)
{
kfree_skb(fp_skb(fp));
}
static inline int fc_frame_is_linear(struct fc_frame *fp)
{
return !skb_is_nonlinear(fp_skb(fp));
}
/*
* Get frame header from message in fc_frame structure.
* This hides a cast and provides a place to add some checking.
*/
static inline
struct fc_frame_header *fc_frame_header_get(const struct fc_frame *fp)
{
WARN_ON(fr_len(fp) < sizeof(struct fc_frame_header));
return (struct fc_frame_header *) fr_hdr(fp);
}
/*
* Get frame payload from message in fc_frame structure.
* This hides a cast and provides a place to add some checking.
* The len parameter is the minimum length for the payload portion.
* Returns NULL if the frame is too short.
*
* This assumes the interesting part of the payload is in the first part
* of the buffer for received data. This may not be appropriate to use for
* buffers being transmitted.
*/
static inline void *fc_frame_payload_get(const struct fc_frame *fp,
size_t len)
{
void *pp = NULL;
if (fr_len(fp) >= sizeof(struct fc_frame_header) + len)
pp = fc_frame_header_get(fp) + 1;
return pp;
}
/*
* Get frame payload opcode (first byte) from message in fc_frame structure.
* This hides a cast and provides a place to add some checking. Return 0
* if the frame has no payload.
*/
static inline u8 fc_frame_payload_op(const struct fc_frame *fp)
{
u8 *cp;
cp = fc_frame_payload_get(fp, sizeof(u8));
if (!cp)
return 0;
return *cp;
}
/*
* Get FC class from frame.
*/
static inline enum fc_class fc_frame_class(const struct fc_frame *fp)
{
return fc_sof_class(fr_sof(fp));
}
/*
* Check the CRC in a frame.
* The CRC immediately follows the last data item *AFTER* the length.
* The return value is zero if the CRC matches.
*/
u32 fc_frame_crc_check(struct fc_frame *);
static inline u8 fc_frame_rctl(const struct fc_frame *fp)
{
return fc_frame_header_get(fp)->fh_r_ctl;
}
static inline bool fc_frame_is_cmd(const struct fc_frame *fp)
{
return fc_frame_rctl(fp) == FC_RCTL_DD_UNSOL_CMD;
}
/*
* Check for leaks.
* Print the frame header of any currently allocated frame, assuming there
* should be none at this point.
*/
void fc_frame_leak_check(void);
#endif /* _FC_FRAME_H_ */
