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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright(c) 2007 Intel Corporation. All rights reserved.
4 *
5 * Maintained at www.Open-FCoE.org
6 */
7
8/*
9 * Frame allocation.
10 */
11#include <linux/module.h>
12#include <linux/kernel.h>
13#include <linux/skbuff.h>
14#include <linux/crc32.h>
15#include <linux/gfp.h>
16
17#include <scsi/fc_frame.h>
18
19/*
20 * Check the CRC in a frame.
21 */
22u32 fc_frame_crc_check(struct fc_frame *fp)
23{
24 u32 crc;
25 u32 error;
26 const u8 *bp;
27 unsigned int len;
28
29 WARN_ON(!fc_frame_is_linear(fp));
30 fr_flags(fp) &= ~FCPHF_CRC_UNCHECKED;
31 len = (fr_len(fp) + 3) & ~3; /* round up length to include fill */
32 bp = (const u8 *) fr_hdr(fp);
33 crc = ~crc32(~0, bp, len);
34 error = crc ^ fr_crc(fp);
35 return error;
36}
37EXPORT_SYMBOL(fc_frame_crc_check);
38
39/*
40 * Allocate a frame intended to be sent.
41 * Get an sk_buff for the frame and set the length.
42 */
43struct fc_frame *_fc_frame_alloc(size_t len)
44{
45 struct fc_frame *fp;
46 struct sk_buff *skb;
47
48 WARN_ON((len % sizeof(u32)) != 0);
49 len += sizeof(struct fc_frame_header);
50 skb = alloc_skb_fclone(len + FC_FRAME_HEADROOM + FC_FRAME_TAILROOM +
51 NET_SKB_PAD, GFP_ATOMIC);
52 if (!skb)
53 return NULL;
54 skb_reserve(skb, NET_SKB_PAD + FC_FRAME_HEADROOM);
55 fp = (struct fc_frame *) skb;
56 fc_frame_init(fp);
57 skb_put(skb, len);
58 return fp;
59}
60EXPORT_SYMBOL(_fc_frame_alloc);
61
62struct fc_frame *fc_frame_alloc_fill(struct fc_lport *lp, size_t payload_len)
63{
64 struct fc_frame *fp;
65 size_t fill;
66
67 fill = payload_len % 4;
68 if (fill != 0)
69 fill = 4 - fill;
70 fp = _fc_frame_alloc(payload_len + fill);
71 if (fp) {
72 memset((char *) fr_hdr(fp) + payload_len, 0, fill);
73 /* trim is OK, we just allocated it so there are no fragments */
74 skb_trim(fp_skb(fp),
75 payload_len + sizeof(struct fc_frame_header));
76 }
77 return fp;
78}
79EXPORT_SYMBOL(fc_frame_alloc_fill);