80 lines · c
1// SPDX-License-Identifier: GPL-2.0-only2/*3 * Copyright(c) 2007 Intel Corporation. All rights reserved.4 *5 * Maintained at www.Open-FCoE.org6 */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);80