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// SPDX-License-Identifier: GPL-2.0-or-later
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/vmalloc.h>
#include <linux/zlib.h>
#include "backend_deflate.h"
/* Use the same value as crypto API */
#define DEFLATE_DEF_WINBITS 11
#define DEFLATE_DEF_MEMLEVEL MAX_MEM_LEVEL
struct deflate_ctx {
struct z_stream_s cctx;
struct z_stream_s dctx;
s32 level;
};
static void deflate_destroy(void *ctx)
{
struct deflate_ctx *zctx = ctx;
if (zctx->cctx.workspace) {
zlib_deflateEnd(&zctx->cctx);
vfree(zctx->cctx.workspace);
}
if (zctx->dctx.workspace) {
zlib_inflateEnd(&zctx->dctx);
vfree(zctx->dctx.workspace);
}
kfree(zctx);
}
static void *deflate_create(struct zcomp_params *params)
{
struct deflate_ctx *ctx;
size_t sz;
int ret;
ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
if (!ctx)
return NULL;
if (params->level != ZCOMP_PARAM_NO_LEVEL)
ctx->level = params->level;
else
ctx->level = Z_DEFAULT_COMPRESSION;
sz = zlib_deflate_workspacesize(-DEFLATE_DEF_WINBITS, MAX_MEM_LEVEL);
ctx->cctx.workspace = vzalloc(sz);
if (!ctx->cctx.workspace)
goto error;
ret = zlib_deflateInit2(&ctx->cctx, ctx->level, Z_DEFLATED,
-DEFLATE_DEF_WINBITS, DEFLATE_DEF_MEMLEVEL,
Z_DEFAULT_STRATEGY);
if (ret != Z_OK)
goto error;
sz = zlib_inflate_workspacesize();
ctx->dctx.workspace = vzalloc(sz);
if (!ctx->dctx.workspace)
goto error;
ret = zlib_inflateInit2(&ctx->dctx, -DEFLATE_DEF_WINBITS);
if (ret != Z_OK)
goto error;
return ctx;
error:
deflate_destroy(ctx);
return NULL;
}
static int deflate_compress(void *ctx, const unsigned char *src,
size_t src_len, unsigned char *dst,
size_t *dst_len)
{
struct deflate_ctx *zctx = ctx;
struct z_stream_s *deflate;
int ret;
deflate = &zctx->cctx;
ret = zlib_deflateReset(deflate);
if (ret != Z_OK)
return -EINVAL;
deflate->next_in = (u8 *)src;
deflate->avail_in = src_len;
deflate->next_out = (u8 *)dst;
deflate->avail_out = *dst_len;
ret = zlib_deflate(deflate, Z_FINISH);
if (ret != Z_STREAM_END)
return -EINVAL;
*dst_len = deflate->total_out;
return 0;
}
static int deflate_decompress(void *ctx, const unsigned char *src,
size_t src_len, unsigned char *dst,
size_t dst_len)
{
struct deflate_ctx *zctx = ctx;
struct z_stream_s *inflate;
int ret;
inflate = &zctx->dctx;
ret = zlib_inflateReset(inflate);
if (ret != Z_OK)
return -EINVAL;
inflate->next_in = (u8 *)src;
inflate->avail_in = src_len;
inflate->next_out = (u8 *)dst;
inflate->avail_out = dst_len;
ret = zlib_inflate(inflate, Z_SYNC_FLUSH);
if (ret != Z_STREAM_END)
return -EINVAL;
return 0;
}
const struct zcomp_ops backend_deflate = {
.compress = deflate_compress,
.decompress = deflate_decompress,
.create_ctx = deflate_create,
.destroy_ctx = deflate_destroy,
.name = "deflate",
};
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