99 lines
2.2 KiB
C
99 lines
2.2 KiB
C
|
/*
|
||
|
|
* Cryptographic API.
|
||
|
|
*
|
||
|
|
* Cipher operations.
|
||
|
|
*
|
||
|
|
* Copyright (c) 2002 James Morris <jmorris@intercode.com.au>
|
||
|
|
* 2002 Adam J. Richter <adam@yggdrasil.com>
|
||
|
|
* 2004 Jean-Luc Cooke <jlcooke@certainkey.com>
|
||
|
|
*
|
||
|
|
* This program is free software; you can redistribute it and/or modify it
|
||
|
|
* under the terms of the GNU General Public License as published by the Free
|
||
|
|
* Software Foundation; either version 2 of the License, or (at your option)
|
||
|
|
* any later version.
|
||
|
|
*
|
||
|
|
*/
|
||
|
|
|
||
|
|
#include <crypto/scatterwalk.h>
|
||
|
|
#include <linux/kernel.h>
|
||
|
|
#include <linux/mm.h>
|
||
|
|
#include <linux/module.h>
|
||
|
|
#include <linux/scatterlist.h>
|
||
|
|
|
||
|
|
static inline void memcpy_dir(void *buf, void *sgdata, size_t nbytes, int out)
|
||
|
|
{
|
||
|
|
void *src = out ? buf : sgdata;
|
||
|
|
void *dst = out ? sgdata : buf;
|
||
|
|
|
||
|
|
memcpy(dst, src, nbytes);
|
||
|
|
}
|
||
|
|
|
||
|
|
void scatterwalk_copychunks(void *buf, struct scatter_walk *walk,
|
||
|
|
size_t nbytes, int out)
|
||
|
|
{
|
||
|
|
for (;;) {
|
||
|
|
unsigned int len_this_page = scatterwalk_pagelen(walk);
|
||
|
|
u8 *vaddr;
|
||
|
|
|
||
|
|
if (len_this_page > nbytes)
|
||
|
|
len_this_page = nbytes;
|
||
|
|
|
||
|
|
if (out != 2) {
|
||
|
|
vaddr = scatterwalk_map(walk);
|
||
|
|
memcpy_dir(buf, vaddr, len_this_page, out);
|
||
|
|
scatterwalk_unmap(vaddr);
|
||
|
|
}
|
||
|
|
|
||
|
|
scatterwalk_advance(walk, len_this_page);
|
||
|
|
|
||
|
|
if (nbytes == len_this_page)
|
||
|
|
break;
|
||
|
|
|
||
|
|
buf += len_this_page;
|
||
|
|
nbytes -= len_this_page;
|
||
|
|
|
||
|
|
scatterwalk_pagedone(walk, out & 1, 1);
|
||
|
|
}
|
||
|
|
}
|
||
|
|
EXPORT_SYMBOL_GPL(scatterwalk_copychunks);
|
||
|
|
|
||
|
|
void scatterwalk_map_and_copy(void *buf, struct scatterlist *sg,
|
||
|
|
unsigned int start, unsigned int nbytes, int out)
|
||
|
|
{
|
||
|
|
struct scatter_walk walk;
|
||
|
|
struct scatterlist tmp[2];
|
||
|
|
|
||
|
|
if (!nbytes)
|
||
|
|
return;
|
||
|
|
|
||
|
|
sg = scatterwalk_ffwd(tmp, sg, start);
|
||
|
|
|
||
|
|
scatterwalk_start(&walk, sg);
|
||
|
|
scatterwalk_copychunks(buf, &walk, nbytes, out);
|
||
|
|
scatterwalk_done(&walk, out, 0);
|
||
|
|
}
|
||
|
|
EXPORT_SYMBOL_GPL(scatterwalk_map_and_copy);
|
||
|
|
|
||
|
|
struct scatterlist *scatterwalk_ffwd(struct scatterlist dst[2],
|
||
|
|
struct scatterlist *src,
|
||
|
|
unsigned int len)
|
||
|
|
{
|
||
|
|
for (;;) {
|
||
|
|
if (!len)
|
||
|
|
return src;
|
||
|
|
|
||
|
|
if (src->length > len)
|
||
|
|
break;
|
||
|
|
|
||
|
|
len -= src->length;
|
||
|
|
src = sg_next(src);
|
||
|
|
}
|
||
|
|
|
||
|
|
sg_init_table(dst, 2);
|
||
|
|
sg_set_page(dst, sg_page(src), src->length - len, src->offset + len);
|
||
|
|
scatterwalk_crypto_chain(dst, sg_next(src), 0, 2);
|
||
|
|
|
||
|
|
return dst;
|
||
|
|
}
|
||
|
|
EXPORT_SYMBOL_GPL(scatterwalk_ffwd);
|