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yaml
---
r: 196738
b: refs/heads/master
c: bf06099
h: refs/heads/master
v: v3
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David S. Miller authored and Herbert Xu committed May 19, 2010
1 parent f9c1702 commit 36d3135
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Showing 3 changed files with 318 additions and 1 deletion.
2 changes: 1 addition & 1 deletion [refs]
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@@ -1,2 +1,2 @@
---
refs/heads/master: a8f1a05292db8b410be47fa905669672011f0343
refs/heads/master: bf06099db18a1244957076e51847c644cfe46808
277 changes: 277 additions & 0 deletions trunk/crypto/ablkcipher.c
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Expand Up @@ -24,10 +24,287 @@
#include <linux/slab.h>
#include <linux/seq_file.h>

#include <crypto/scatterwalk.h>

#include "internal.h"

static const char *skcipher_default_geniv __read_mostly;

struct ablkcipher_buffer {
struct list_head entry;
struct scatter_walk dst;
unsigned int len;
void *data;
};

enum {
ABLKCIPHER_WALK_SLOW = 1 << 0,
};

static inline void ablkcipher_buffer_write(struct ablkcipher_buffer *p)
{
scatterwalk_copychunks(p->data, &p->dst, p->len, 1);
}

void __ablkcipher_walk_complete(struct ablkcipher_walk *walk)
{
struct ablkcipher_buffer *p, *tmp;

list_for_each_entry_safe(p, tmp, &walk->buffers, entry) {
ablkcipher_buffer_write(p);
list_del(&p->entry);
kfree(p);
}
}
EXPORT_SYMBOL_GPL(__ablkcipher_walk_complete);

static inline void ablkcipher_queue_write(struct ablkcipher_walk *walk,
struct ablkcipher_buffer *p)
{
p->dst = walk->out;
list_add_tail(&p->entry, &walk->buffers);
}

/* Get a spot of the specified length that does not straddle a page.
* The caller needs to ensure that there is enough space for this operation.
*/
static inline u8 *ablkcipher_get_spot(u8 *start, unsigned int len)
{
u8 *end_page = (u8 *)(((unsigned long)(start + len - 1)) & PAGE_MASK);
return max(start, end_page);
}

static inline unsigned int ablkcipher_done_slow(struct ablkcipher_walk *walk,
unsigned int bsize)
{
unsigned int n = bsize;

for (;;) {
unsigned int len_this_page = scatterwalk_pagelen(&walk->out);

if (len_this_page > n)
len_this_page = n;
scatterwalk_advance(&walk->out, n);
if (n == len_this_page)
break;
n -= len_this_page;
scatterwalk_start(&walk->out, scatterwalk_sg_next(walk->out.sg));
}

return bsize;
}

static inline unsigned int ablkcipher_done_fast(struct ablkcipher_walk *walk,
unsigned int n)
{
scatterwalk_advance(&walk->in, n);
scatterwalk_advance(&walk->out, n);

return n;
}

static int ablkcipher_walk_next(struct ablkcipher_request *req,
struct ablkcipher_walk *walk);

int ablkcipher_walk_done(struct ablkcipher_request *req,
struct ablkcipher_walk *walk, int err)
{
struct crypto_tfm *tfm = req->base.tfm;
unsigned int nbytes = 0;

if (likely(err >= 0)) {
unsigned int n = walk->nbytes - err;

if (likely(!(walk->flags & ABLKCIPHER_WALK_SLOW)))
n = ablkcipher_done_fast(walk, n);
else if (WARN_ON(err)) {
err = -EINVAL;
goto err;
} else
n = ablkcipher_done_slow(walk, n);

nbytes = walk->total - n;
err = 0;
}

scatterwalk_done(&walk->in, 0, nbytes);
scatterwalk_done(&walk->out, 1, nbytes);

err:
walk->total = nbytes;
walk->nbytes = nbytes;

if (nbytes) {
crypto_yield(req->base.flags);
return ablkcipher_walk_next(req, walk);
}

if (walk->iv != req->info)
memcpy(req->info, walk->iv, tfm->crt_ablkcipher.ivsize);
if (walk->iv_buffer)
kfree(walk->iv_buffer);

return err;
}
EXPORT_SYMBOL_GPL(ablkcipher_walk_done);

static inline int ablkcipher_next_slow(struct ablkcipher_request *req,
struct ablkcipher_walk *walk,
unsigned int bsize,
unsigned int alignmask,
void **src_p, void **dst_p)
{
unsigned aligned_bsize = ALIGN(bsize, alignmask + 1);
struct ablkcipher_buffer *p;
void *src, *dst, *base;
unsigned int n;

n = ALIGN(sizeof(struct ablkcipher_buffer), alignmask + 1);
n += (aligned_bsize * 3 - (alignmask + 1) +
(alignmask & ~(crypto_tfm_ctx_alignment() - 1)));

p = kmalloc(n, GFP_ATOMIC);
if (!p)
ablkcipher_walk_done(req, walk, -ENOMEM);

base = p + 1;

dst = (u8 *)ALIGN((unsigned long)base, alignmask + 1);
src = dst = ablkcipher_get_spot(dst, bsize);

p->len = bsize;
p->data = dst;

scatterwalk_copychunks(src, &walk->in, bsize, 0);

ablkcipher_queue_write(walk, p);

walk->nbytes = bsize;
walk->flags |= ABLKCIPHER_WALK_SLOW;

*src_p = src;
*dst_p = dst;

return 0;
}

static inline int ablkcipher_copy_iv(struct ablkcipher_walk *walk,
struct crypto_tfm *tfm,
unsigned int alignmask)
{
unsigned bs = walk->blocksize;
unsigned int ivsize = tfm->crt_ablkcipher.ivsize;
unsigned aligned_bs = ALIGN(bs, alignmask + 1);
unsigned int size = aligned_bs * 2 + ivsize + max(aligned_bs, ivsize) -
(alignmask + 1);
u8 *iv;

size += alignmask & ~(crypto_tfm_ctx_alignment() - 1);
walk->iv_buffer = kmalloc(size, GFP_ATOMIC);
if (!walk->iv_buffer)
return -ENOMEM;

iv = (u8 *)ALIGN((unsigned long)walk->iv_buffer, alignmask + 1);
iv = ablkcipher_get_spot(iv, bs) + aligned_bs;
iv = ablkcipher_get_spot(iv, bs) + aligned_bs;
iv = ablkcipher_get_spot(iv, ivsize);

walk->iv = memcpy(iv, walk->iv, ivsize);
return 0;
}

static inline int ablkcipher_next_fast(struct ablkcipher_request *req,
struct ablkcipher_walk *walk)
{
walk->src.page = scatterwalk_page(&walk->in);
walk->src.offset = offset_in_page(walk->in.offset);
walk->dst.page = scatterwalk_page(&walk->out);
walk->dst.offset = offset_in_page(walk->out.offset);

return 0;
}

static int ablkcipher_walk_next(struct ablkcipher_request *req,
struct ablkcipher_walk *walk)
{
struct crypto_tfm *tfm = req->base.tfm;
unsigned int alignmask, bsize, n;
void *src, *dst;
int err;

alignmask = crypto_tfm_alg_alignmask(tfm);
n = walk->total;
if (unlikely(n < crypto_tfm_alg_blocksize(tfm))) {
req->base.flags |= CRYPTO_TFM_RES_BAD_BLOCK_LEN;
return ablkcipher_walk_done(req, walk, -EINVAL);
}

walk->flags &= ~ABLKCIPHER_WALK_SLOW;
src = dst = NULL;

bsize = min(walk->blocksize, n);
n = scatterwalk_clamp(&walk->in, n);
n = scatterwalk_clamp(&walk->out, n);

if (n < bsize ||
!scatterwalk_aligned(&walk->in, alignmask) ||
!scatterwalk_aligned(&walk->out, alignmask)) {
err = ablkcipher_next_slow(req, walk, bsize, alignmask,
&src, &dst);
goto set_phys_lowmem;
}

walk->nbytes = n;

return ablkcipher_next_fast(req, walk);

set_phys_lowmem:
if (err >= 0) {
walk->src.page = virt_to_page(src);
walk->dst.page = virt_to_page(dst);
walk->src.offset = ((unsigned long)src & (PAGE_SIZE - 1));
walk->dst.offset = ((unsigned long)dst & (PAGE_SIZE - 1));
}

return err;
}

static int ablkcipher_walk_first(struct ablkcipher_request *req,
struct ablkcipher_walk *walk)
{
struct crypto_tfm *tfm = req->base.tfm;
unsigned int alignmask;

alignmask = crypto_tfm_alg_alignmask(tfm);
if (WARN_ON_ONCE(in_irq()))
return -EDEADLK;

walk->nbytes = walk->total;
if (unlikely(!walk->total))
return 0;

walk->iv_buffer = NULL;
walk->iv = req->info;
if (unlikely(((unsigned long)walk->iv & alignmask))) {
int err = ablkcipher_copy_iv(walk, tfm, alignmask);
if (err)
return err;
}

scatterwalk_start(&walk->in, walk->in.sg);
scatterwalk_start(&walk->out, walk->out.sg);

return ablkcipher_walk_next(req, walk);
}

int ablkcipher_walk_phys(struct ablkcipher_request *req,
struct ablkcipher_walk *walk)
{
walk->blocksize = crypto_tfm_alg_blocksize(req->base.tfm);
return ablkcipher_walk_first(req, walk);
}
EXPORT_SYMBOL_GPL(ablkcipher_walk_phys);

static int setkey_unaligned(struct crypto_ablkcipher *tfm, const u8 *key,
unsigned int keylen)
{
Expand Down
40 changes: 40 additions & 0 deletions trunk/include/crypto/algapi.h
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Original file line number Diff line number Diff line change
Expand Up @@ -103,6 +103,23 @@ struct blkcipher_walk {
unsigned int blocksize;
};

struct ablkcipher_walk {
struct {
struct page *page;
unsigned int offset;
} src, dst;

struct scatter_walk in;
unsigned int nbytes;
struct scatter_walk out;
unsigned int total;
struct list_head buffers;
u8 *iv_buffer;
u8 *iv;
int flags;
unsigned int blocksize;
};

extern const struct crypto_type crypto_ablkcipher_type;
extern const struct crypto_type crypto_aead_type;
extern const struct crypto_type crypto_blkcipher_type;
Expand Down Expand Up @@ -173,6 +190,12 @@ int blkcipher_walk_virt_block(struct blkcipher_desc *desc,
struct blkcipher_walk *walk,
unsigned int blocksize);

int ablkcipher_walk_done(struct ablkcipher_request *req,
struct ablkcipher_walk *walk, int err);
int ablkcipher_walk_phys(struct ablkcipher_request *req,
struct ablkcipher_walk *walk);
void __ablkcipher_walk_complete(struct ablkcipher_walk *walk);

static inline void *crypto_tfm_ctx_aligned(struct crypto_tfm *tfm)
{
return PTR_ALIGN(crypto_tfm_ctx(tfm),
Expand Down Expand Up @@ -283,6 +306,23 @@ static inline void blkcipher_walk_init(struct blkcipher_walk *walk,
walk->total = nbytes;
}

static inline void ablkcipher_walk_init(struct ablkcipher_walk *walk,
struct scatterlist *dst,
struct scatterlist *src,
unsigned int nbytes)
{
walk->in.sg = src;
walk->out.sg = dst;
walk->total = nbytes;
INIT_LIST_HEAD(&walk->buffers);
}

static inline void ablkcipher_walk_complete(struct ablkcipher_walk *walk)
{
if (unlikely(!list_empty(&walk->buffers)))
__ablkcipher_walk_complete(walk);
}

static inline struct crypto_async_request *crypto_get_backlog(
struct crypto_queue *queue)
{
Expand Down

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