90 строки
2.3 KiB
C
90 строки
2.3 KiB
C
/*
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* Copyright(c) 2007 Intel Corporation. All rights reserved.
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*
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* This program is free software; you can redistribute it and/or modify it
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* under the terms and conditions of the GNU General Public License,
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* version 2, as published by the Free Software Foundation.
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*
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* This program is distributed in the hope it will be useful, but WITHOUT
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* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
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* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
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* more details.
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*
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* You should have received a copy of the GNU General Public License along with
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* this program; if not, write to the Free Software Foundation, Inc.,
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* 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
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*
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* Maintained at www.Open-FCoE.org
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*/
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/*
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* Frame allocation.
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*/
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#include <linux/module.h>
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#include <linux/kernel.h>
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#include <linux/skbuff.h>
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#include <linux/crc32.h>
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#include <scsi/fc_frame.h>
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/*
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* Check the CRC in a frame.
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*/
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u32 fc_frame_crc_check(struct fc_frame *fp)
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{
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u32 crc;
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u32 error;
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const u8 *bp;
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unsigned int len;
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WARN_ON(!fc_frame_is_linear(fp));
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fr_flags(fp) &= ~FCPHF_CRC_UNCHECKED;
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len = (fr_len(fp) + 3) & ~3; /* round up length to include fill */
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bp = (const u8 *) fr_hdr(fp);
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crc = ~crc32(~0, bp, len);
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error = crc ^ fr_crc(fp);
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return error;
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}
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EXPORT_SYMBOL(fc_frame_crc_check);
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/*
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* Allocate a frame intended to be sent via fcoe_xmit.
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* Get an sk_buff for the frame and set the length.
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*/
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struct fc_frame *__fc_frame_alloc(size_t len)
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{
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struct fc_frame *fp;
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struct sk_buff *skb;
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WARN_ON((len % sizeof(u32)) != 0);
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len += sizeof(struct fc_frame_header);
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skb = dev_alloc_skb(len + FC_FRAME_HEADROOM + FC_FRAME_TAILROOM);
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if (!skb)
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return NULL;
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fp = (struct fc_frame *) skb;
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fc_frame_init(fp);
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skb_reserve(skb, FC_FRAME_HEADROOM);
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skb_put(skb, len);
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return fp;
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}
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EXPORT_SYMBOL(__fc_frame_alloc);
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struct fc_frame *fc_frame_alloc_fill(struct fc_lport *lp, size_t payload_len)
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{
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struct fc_frame *fp;
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size_t fill;
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fill = payload_len % 4;
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if (fill != 0)
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fill = 4 - fill;
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fp = __fc_frame_alloc(payload_len + fill);
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if (fp) {
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memset((char *) fr_hdr(fp) + payload_len, 0, fill);
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/* trim is OK, we just allocated it so there are no fragments */
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skb_trim(fp_skb(fp),
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payload_len + sizeof(struct fc_frame_header));
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}
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return fp;
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}
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