| Robert Love | 42e9a92 | 2008-12-09 15:10:17 -0800 | [diff] [blame] | 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> |
| 27 | |
| 28 | #include <scsi/fc_frame.h> |
| 29 | |
| 30 | /* |
| 31 | * Check the CRC in a frame. |
| 32 | */ |
| 33 | u32 fc_frame_crc_check(struct fc_frame *fp) |
| 34 | { |
| 35 | u32 crc; |
| 36 | u32 error; |
| 37 | const u8 *bp; |
| 38 | unsigned int len; |
| 39 | |
| 40 | WARN_ON(!fc_frame_is_linear(fp)); |
| 41 | fr_flags(fp) &= ~FCPHF_CRC_UNCHECKED; |
| 42 | len = (fr_len(fp) + 3) & ~3; /* round up length to include fill */ |
| 43 | bp = (const u8 *) fr_hdr(fp); |
| 44 | crc = ~crc32(~0, bp, len); |
| 45 | error = crc ^ fr_crc(fp); |
| 46 | return error; |
| 47 | } |
| 48 | EXPORT_SYMBOL(fc_frame_crc_check); |
| 49 | |
| 50 | /* |
| 51 | * Allocate a frame intended to be sent via fcoe_xmit. |
| 52 | * Get an sk_buff for the frame and set the length. |
| 53 | */ |
| 54 | struct fc_frame *__fc_frame_alloc(size_t len) |
| 55 | { |
| 56 | struct fc_frame *fp; |
| 57 | struct sk_buff *skb; |
| 58 | |
| 59 | WARN_ON((len % sizeof(u32)) != 0); |
| 60 | len += sizeof(struct fc_frame_header); |
| 61 | skb = dev_alloc_skb(len + FC_FRAME_HEADROOM + FC_FRAME_TAILROOM); |
| 62 | if (!skb) |
| 63 | return NULL; |
| 64 | fp = (struct fc_frame *) skb; |
| 65 | fc_frame_init(fp); |
| 66 | skb_reserve(skb, FC_FRAME_HEADROOM); |
| 67 | skb_put(skb, len); |
| 68 | return fp; |
| 69 | } |
| 70 | EXPORT_SYMBOL(__fc_frame_alloc); |
| 71 | |
| 72 | |
| 73 | struct fc_frame *fc_frame_alloc_fill(struct fc_lport *lp, size_t payload_len) |
| 74 | { |
| 75 | struct fc_frame *fp; |
| 76 | size_t fill; |
| 77 | |
| 78 | fill = payload_len % 4; |
| 79 | if (fill != 0) |
| 80 | fill = 4 - fill; |
| 81 | fp = __fc_frame_alloc(payload_len + fill); |
| 82 | if (fp) { |
| 83 | memset((char *) fr_hdr(fp) + payload_len, 0, fill); |
| 84 | /* trim is OK, we just allocated it so there are no fragments */ |
| 85 | skb_trim(fp_skb(fp), |
| 86 | payload_len + sizeof(struct fc_frame_header)); |
| 87 | } |
| 88 | return fp; |
| 89 | } |