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/*
* 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
*/
/*
* Frame allocation.
*/
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/skbuff.h>
#include <linux/crc32.h>
#include <scsi/fc_frame.h>
/*
* Check the CRC in a frame.
*/
u32 fc_frame_crc_check(struct fc_frame *fp)
{
u32 crc;
u32 error;
const u8 *bp;
unsigned int len;
WARN_ON(!fc_frame_is_linear(fp));
fr_flags(fp) &= ~FCPHF_CRC_UNCHECKED;
len = (fr_len(fp) + 3) & ~3; /* round up length to include fill */
bp = (const u8 *) fr_hdr(fp);
crc = ~crc32(~0, bp, len);
error = crc ^ fr_crc(fp);
return error;
}
EXPORT_SYMBOL(fc_frame_crc_check);
/*
* Allocate a frame intended to be sent via fcoe_xmit.
* Get an sk_buff for the frame and set the length.
*/
struct fc_frame *__fc_frame_alloc(size_t len)
{
struct fc_frame *fp;
struct sk_buff *skb;
WARN_ON((len % sizeof(u32)) != 0);
len += sizeof(struct fc_frame_header);
skb = dev_alloc_skb(len + FC_FRAME_HEADROOM + FC_FRAME_TAILROOM);
if (!skb)
return NULL;
fp = (struct fc_frame *) skb;
fc_frame_init(fp);
skb_reserve(skb, FC_FRAME_HEADROOM);
skb_put(skb, len);
return fp;
}
EXPORT_SYMBOL(__fc_frame_alloc);
struct fc_frame *fc_frame_alloc_fill(struct fc_lport *lp, size_t payload_len)
{
struct fc_frame *fp;
size_t fill;
fill = payload_len % 4;
if (fill != 0)
fill = 4 - fill;
fp = __fc_frame_alloc(payload_len + fill);
if (fp) {
memset((char *) fr_hdr(fp) + payload_len, 0, fill);
/* trim is OK, we just allocated it so there are no fragments */
skb_trim(fp_skb(fp),
payload_len + sizeof(struct fc_frame_header));
}
return fp;
}
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