blob: 0382ac06906ed4b36760df1970025a91a81c9282 [file] [log] [blame]
Robert Love42e9a922008-12-09 15:10:17 -08001/*
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/*
21 * Frame allocation.
22 */
23#include <linux/module.h>
24#include <linux/kernel.h>
25#include <linux/skbuff.h>
26#include <linux/crc32.h>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090027#include <linux/gfp.h>
Robert Love42e9a922008-12-09 15:10:17 -080028
29#include <scsi/fc_frame.h>
30
31/*
32 * Check the CRC in a frame.
33 */
34u32 fc_frame_crc_check(struct fc_frame *fp)
35{
36 u32 crc;
37 u32 error;
38 const u8 *bp;
39 unsigned int len;
40
41 WARN_ON(!fc_frame_is_linear(fp));
42 fr_flags(fp) &= ~FCPHF_CRC_UNCHECKED;
43 len = (fr_len(fp) + 3) & ~3; /* round up length to include fill */
44 bp = (const u8 *) fr_hdr(fp);
45 crc = ~crc32(~0, bp, len);
46 error = crc ^ fr_crc(fp);
47 return error;
48}
49EXPORT_SYMBOL(fc_frame_crc_check);
50
51/*
Vasu Dev1bd49b42012-05-25 10:26:43 -070052 * Allocate a frame intended to be sent.
Robert Love42e9a922008-12-09 15:10:17 -080053 * Get an sk_buff for the frame and set the length.
54 */
Vasu Deva7bbc7f2009-11-03 11:47:55 -080055struct fc_frame *_fc_frame_alloc(size_t len)
Robert Love42e9a922008-12-09 15:10:17 -080056{
57 struct fc_frame *fp;
58 struct sk_buff *skb;
59
60 WARN_ON((len % sizeof(u32)) != 0);
61 len += sizeof(struct fc_frame_header);
Chris Leech18fa11e2009-11-03 11:50:05 -080062 skb = alloc_skb_fclone(len + FC_FRAME_HEADROOM + FC_FRAME_TAILROOM +
63 NET_SKB_PAD, GFP_ATOMIC);
Robert Love42e9a922008-12-09 15:10:17 -080064 if (!skb)
65 return NULL;
Chris Leech18fa11e2009-11-03 11:50:05 -080066 skb_reserve(skb, NET_SKB_PAD + FC_FRAME_HEADROOM);
Robert Love42e9a922008-12-09 15:10:17 -080067 fp = (struct fc_frame *) skb;
68 fc_frame_init(fp);
Robert Love42e9a922008-12-09 15:10:17 -080069 skb_put(skb, len);
70 return fp;
71}
Vasu Deva7bbc7f2009-11-03 11:47:55 -080072EXPORT_SYMBOL(_fc_frame_alloc);
Robert Love42e9a922008-12-09 15:10:17 -080073
Robert Love42e9a922008-12-09 15:10:17 -080074struct fc_frame *fc_frame_alloc_fill(struct fc_lport *lp, size_t payload_len)
75{
76 struct fc_frame *fp;
77 size_t fill;
78
79 fill = payload_len % 4;
80 if (fill != 0)
81 fill = 4 - fill;
Vasu Deva7bbc7f2009-11-03 11:47:55 -080082 fp = _fc_frame_alloc(payload_len + fill);
Robert Love42e9a922008-12-09 15:10:17 -080083 if (fp) {
84 memset((char *) fr_hdr(fp) + payload_len, 0, fill);
85 /* trim is OK, we just allocated it so there are no fragments */
86 skb_trim(fp_skb(fp),
87 payload_len + sizeof(struct fc_frame_header));
88 }
89 return fp;
90}
Chris Leechdc8596d2009-11-03 11:47:18 -080091EXPORT_SYMBOL(fc_frame_alloc_fill);