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42e9a92f RL |
1 | /* |
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> | |
5a0e3ad6 | 27 | #include <linux/gfp.h> |
42e9a92f RL |
28 | |
29 | #include <scsi/fc_frame.h> | |
30 | ||
31 | /* | |
32 | * Check the CRC in a frame. | |
33 | */ | |
34 | u32 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 | } | |
49 | EXPORT_SYMBOL(fc_frame_crc_check); | |
50 | ||
51 | /* | |
1bd49b48 | 52 | * Allocate a frame intended to be sent. |
42e9a92f RL |
53 | * Get an sk_buff for the frame and set the length. |
54 | */ | |
a7bbc7f4 | 55 | struct fc_frame *_fc_frame_alloc(size_t len) |
42e9a92f RL |
56 | { |
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); | |
18fa11ef CL |
62 | skb = alloc_skb_fclone(len + FC_FRAME_HEADROOM + FC_FRAME_TAILROOM + |
63 | NET_SKB_PAD, GFP_ATOMIC); | |
42e9a92f RL |
64 | if (!skb) |
65 | return NULL; | |
18fa11ef | 66 | skb_reserve(skb, NET_SKB_PAD + FC_FRAME_HEADROOM); |
42e9a92f RL |
67 | fp = (struct fc_frame *) skb; |
68 | fc_frame_init(fp); | |
42e9a92f RL |
69 | skb_put(skb, len); |
70 | return fp; | |
71 | } | |
a7bbc7f4 | 72 | EXPORT_SYMBOL(_fc_frame_alloc); |
42e9a92f | 73 | |
42e9a92f RL |
74 | struct 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; | |
a7bbc7f4 | 82 | fp = _fc_frame_alloc(payload_len + fill); |
42e9a92f RL |
83 | 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 | } | |
dc8596d3 | 91 | EXPORT_SYMBOL(fc_frame_alloc_fill); |