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// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Cryptographic API.
*
* Deflate algorithm (RFC 1951), implemented here primarily for use
* by IPCOMP (RFC 3173 & RFC 2394).
*
* Copyright (c) 2003 James Morris <jmorris@intercode.com.au>
* Copyright (c) 2023 Google, LLC. <ardb@kernel.org>
* Copyright (c) 2025 Herbert Xu <herbert@gondor.apana.org.au>
*/
#include <crypto/internal/acompress.h>
#include <crypto/scatterwalk.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/percpu.h>
#include <linux/scatterlist.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/zlib.h>
#define DEFLATE_DEF_LEVEL Z_DEFAULT_COMPRESSION
#define DEFLATE_DEF_WINBITS 11
#define DEFLATE_DEF_MEMLEVEL MAX_MEM_LEVEL
struct deflate_stream {
struct z_stream_s stream;
u8 workspace[];
};
static DEFINE_MUTEX(deflate_stream_lock);
static void *deflate_alloc_stream(void)
{
size_t size = max(zlib_inflate_workspacesize(),
zlib_deflate_workspacesize(-DEFLATE_DEF_WINBITS,
DEFLATE_DEF_MEMLEVEL));
struct deflate_stream *ctx;
ctx = kvmalloc(sizeof(*ctx) + size, GFP_KERNEL);
if (!ctx)
return ERR_PTR(-ENOMEM);
ctx->stream.workspace = ctx->workspace;
return ctx;
}
static struct crypto_acomp_streams deflate_streams = {
.alloc_ctx = deflate_alloc_stream,
.cfree_ctx = kvfree,
};
static int deflate_compress_one(struct acomp_req *req,
struct deflate_stream *ds)
{
struct z_stream_s *stream = &ds->stream;
struct acomp_walk walk;
int ret;
ret = acomp_walk_virt(&walk, req, true);
if (ret)
return ret;
do {
unsigned int dcur;
dcur = acomp_walk_next_dst(&walk);
if (!dcur)
return -ENOSPC;
stream->avail_out = dcur;
stream->next_out = walk.dst.virt.addr;
do {
int flush = Z_FINISH;
unsigned int scur;
stream->avail_in = 0;
stream->next_in = NULL;
scur = acomp_walk_next_src(&walk);
if (scur) {
if (acomp_walk_more_src(&walk, scur))
flush = Z_NO_FLUSH;
stream->avail_in = scur;
stream->next_in = walk.src.virt.addr;
}
ret = zlib_deflate(stream, flush);
if (scur) {
scur -= stream->avail_in;
acomp_walk_done_src(&walk, scur);
}
} while (ret == Z_OK && stream->avail_out);
acomp_walk_done_dst(&walk, dcur);
} while (ret == Z_OK);
if (ret != Z_STREAM_END)
return -EINVAL;
req->dlen = stream->total_out;
return 0;
}
static int deflate_compress(struct acomp_req *req)
{
struct crypto_acomp_stream *s;
struct deflate_stream *ds;
int err;
s = crypto_acomp_lock_stream_bh(&deflate_streams);
ds = s->ctx;
err = zlib_deflateInit2(&ds->stream, DEFLATE_DEF_LEVEL, Z_DEFLATED,
-DEFLATE_DEF_WINBITS, DEFLATE_DEF_MEMLEVEL,
Z_DEFAULT_STRATEGY);
if (err != Z_OK) {
err = -EINVAL;
goto out;
}
err = deflate_compress_one(req, ds);
out:
crypto_acomp_unlock_stream_bh(s);
return err;
}
static int deflate_decompress_one(struct acomp_req *req,
struct deflate_stream *ds)
{
struct z_stream_s *stream = &ds->stream;
bool out_of_space = false;
struct acomp_walk walk;
int ret;
ret = acomp_walk_virt(&walk, req, true);
if (ret)
return ret;
do {
unsigned int scur;
stream->avail_in = 0;
stream->next_in = NULL;
scur = acomp_walk_next_src(&walk);
if (scur) {
stream->avail_in = scur;
stream->next_in = walk.src.virt.addr;
}
do {
unsigned int dcur;
dcur = acomp_walk_next_dst(&walk);
if (!dcur) {
out_of_space = true;
break;
}
stream->avail_out = dcur;
stream->next_out = walk.dst.virt.addr;
ret = zlib_inflate(stream, Z_NO_FLUSH);
dcur -= stream->avail_out;
acomp_walk_done_dst(&walk, dcur);
} while (ret == Z_OK && stream->avail_in);
if (scur)
acomp_walk_done_src(&walk, scur);
if (out_of_space)
return -ENOSPC;
} while (ret == Z_OK);
if (ret != Z_STREAM_END)
return -EINVAL;
req->dlen = stream->total_out;
return 0;
}
static int deflate_decompress(struct acomp_req *req)
{
struct crypto_acomp_stream *s;
struct deflate_stream *ds;
int err;
s = crypto_acomp_lock_stream_bh(&deflate_streams);
ds = s->ctx;
err = zlib_inflateInit2(&ds->stream, -DEFLATE_DEF_WINBITS);
if (err != Z_OK) {
err = -EINVAL;
goto out;
}
err = deflate_decompress_one(req, ds);
out:
crypto_acomp_unlock_stream_bh(s);
return err;
}
static int deflate_init(struct crypto_acomp *tfm)
{
int ret;
mutex_lock(&deflate_stream_lock);
ret = crypto_acomp_alloc_streams(&deflate_streams);
mutex_unlock(&deflate_stream_lock);
return ret;
}
static struct acomp_alg acomp = {
.compress = deflate_compress,
.decompress = deflate_decompress,
.init = deflate_init,
.base.cra_name = "deflate",
.base.cra_driver_name = "deflate-generic",
.base.cra_flags = CRYPTO_ALG_REQ_VIRT,
.base.cra_module = THIS_MODULE,
};
static int __init deflate_mod_init(void)
{
return crypto_register_acomp(&acomp);
}
static void __exit deflate_mod_fini(void)
{
crypto_unregister_acomp(&acomp);
crypto_acomp_free_streams(&deflate_streams);
}
module_init(deflate_mod_init);
module_exit(deflate_mod_fini);
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("Deflate Compression Algorithm for IPCOMP");
MODULE_AUTHOR("James Morris <jmorris@intercode.com.au>");
MODULE_AUTHOR("Ard Biesheuvel <ardb@kernel.org>");
MODULE_AUTHOR("Herbert Xu <herbert@gondor.apana.org.au>");
MODULE_ALIAS_CRYPTO("deflate");
MODULE_ALIAS_CRYPTO("deflate-generic");
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