diff options
Diffstat (limited to 'kernel/crypto/zlib.c')
| -rw-r--r-- | kernel/crypto/zlib.c | 381 |
1 files changed, 381 insertions, 0 deletions
diff --git a/kernel/crypto/zlib.c b/kernel/crypto/zlib.c new file mode 100644 index 000000000..0eefa9d23 --- /dev/null +++ b/kernel/crypto/zlib.c @@ -0,0 +1,381 @@ +/* + * Cryptographic API. + * + * Zlib algorithm + * + * Copyright 2008 Sony Corporation + * + * Based on deflate.c, which is + * Copyright (c) 2003 James Morris <jmorris@intercode.com.au> + * + * 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. + * + * FIXME: deflate transforms will require up to a total of about 436k of kernel + * memory on i386 (390k for compression, the rest for decompression), as the + * current zlib kernel code uses a worst case pre-allocation system by default. + * This needs to be fixed so that the amount of memory required is properly + * related to the winbits and memlevel parameters. + */ + +#define pr_fmt(fmt) "%s: " fmt, __func__ + +#include <linux/init.h> +#include <linux/module.h> +#include <linux/zlib.h> +#include <linux/vmalloc.h> +#include <linux/interrupt.h> +#include <linux/mm.h> +#include <linux/net.h> + +#include <crypto/internal/compress.h> + +#include <net/netlink.h> + + +struct zlib_ctx { + struct z_stream_s comp_stream; + struct z_stream_s decomp_stream; + int decomp_windowBits; +}; + + +static void zlib_comp_exit(struct zlib_ctx *ctx) +{ + struct z_stream_s *stream = &ctx->comp_stream; + + if (stream->workspace) { + zlib_deflateEnd(stream); + vfree(stream->workspace); + stream->workspace = NULL; + } +} + +static void zlib_decomp_exit(struct zlib_ctx *ctx) +{ + struct z_stream_s *stream = &ctx->decomp_stream; + + if (stream->workspace) { + zlib_inflateEnd(stream); + vfree(stream->workspace); + stream->workspace = NULL; + } +} + +static int zlib_init(struct crypto_tfm *tfm) +{ + return 0; +} + +static void zlib_exit(struct crypto_tfm *tfm) +{ + struct zlib_ctx *ctx = crypto_tfm_ctx(tfm); + + zlib_comp_exit(ctx); + zlib_decomp_exit(ctx); +} + + +static int zlib_compress_setup(struct crypto_pcomp *tfm, void *params, + unsigned int len) +{ + struct zlib_ctx *ctx = crypto_tfm_ctx(crypto_pcomp_tfm(tfm)); + struct z_stream_s *stream = &ctx->comp_stream; + struct nlattr *tb[ZLIB_COMP_MAX + 1]; + int window_bits, mem_level; + size_t workspacesize; + int ret; + + ret = nla_parse(tb, ZLIB_COMP_MAX, params, len, NULL); + if (ret) + return ret; + + zlib_comp_exit(ctx); + + window_bits = tb[ZLIB_COMP_WINDOWBITS] + ? nla_get_u32(tb[ZLIB_COMP_WINDOWBITS]) + : MAX_WBITS; + mem_level = tb[ZLIB_COMP_MEMLEVEL] + ? nla_get_u32(tb[ZLIB_COMP_MEMLEVEL]) + : DEF_MEM_LEVEL; + + workspacesize = zlib_deflate_workspacesize(window_bits, mem_level); + stream->workspace = vzalloc(workspacesize); + if (!stream->workspace) + return -ENOMEM; + + ret = zlib_deflateInit2(stream, + tb[ZLIB_COMP_LEVEL] + ? nla_get_u32(tb[ZLIB_COMP_LEVEL]) + : Z_DEFAULT_COMPRESSION, + tb[ZLIB_COMP_METHOD] + ? nla_get_u32(tb[ZLIB_COMP_METHOD]) + : Z_DEFLATED, + window_bits, + mem_level, + tb[ZLIB_COMP_STRATEGY] + ? nla_get_u32(tb[ZLIB_COMP_STRATEGY]) + : Z_DEFAULT_STRATEGY); + if (ret != Z_OK) { + vfree(stream->workspace); + stream->workspace = NULL; + return -EINVAL; + } + + return 0; +} + +static int zlib_compress_init(struct crypto_pcomp *tfm) +{ + int ret; + struct zlib_ctx *dctx = crypto_tfm_ctx(crypto_pcomp_tfm(tfm)); + struct z_stream_s *stream = &dctx->comp_stream; + + ret = zlib_deflateReset(stream); + if (ret != Z_OK) + return -EINVAL; + + return 0; +} + +static int zlib_compress_update(struct crypto_pcomp *tfm, + struct comp_request *req) +{ + int ret; + struct zlib_ctx *dctx = crypto_tfm_ctx(crypto_pcomp_tfm(tfm)); + struct z_stream_s *stream = &dctx->comp_stream; + + pr_debug("avail_in %u, avail_out %u\n", req->avail_in, req->avail_out); + stream->next_in = req->next_in; + stream->avail_in = req->avail_in; + stream->next_out = req->next_out; + stream->avail_out = req->avail_out; + + ret = zlib_deflate(stream, Z_NO_FLUSH); + switch (ret) { + case Z_OK: + break; + + case Z_BUF_ERROR: + pr_debug("zlib_deflate could not make progress\n"); + return -EAGAIN; + + default: + pr_debug("zlib_deflate failed %d\n", ret); + return -EINVAL; + } + + ret = req->avail_out - stream->avail_out; + pr_debug("avail_in %lu, avail_out %lu (consumed %lu, produced %u)\n", + stream->avail_in, stream->avail_out, + req->avail_in - stream->avail_in, ret); + req->next_in = stream->next_in; + req->avail_in = stream->avail_in; + req->next_out = stream->next_out; + req->avail_out = stream->avail_out; + return ret; +} + +static int zlib_compress_final(struct crypto_pcomp *tfm, + struct comp_request *req) +{ + int ret; + struct zlib_ctx *dctx = crypto_tfm_ctx(crypto_pcomp_tfm(tfm)); + struct z_stream_s *stream = &dctx->comp_stream; + + pr_debug("avail_in %u, avail_out %u\n", req->avail_in, req->avail_out); + stream->next_in = req->next_in; + stream->avail_in = req->avail_in; + stream->next_out = req->next_out; + stream->avail_out = req->avail_out; + + ret = zlib_deflate(stream, Z_FINISH); + if (ret != Z_STREAM_END) { + pr_debug("zlib_deflate failed %d\n", ret); + return -EINVAL; + } + + ret = req->avail_out - stream->avail_out; + pr_debug("avail_in %lu, avail_out %lu (consumed %lu, produced %u)\n", + stream->avail_in, stream->avail_out, + req->avail_in - stream->avail_in, ret); + req->next_in = stream->next_in; + req->avail_in = stream->avail_in; + req->next_out = stream->next_out; + req->avail_out = stream->avail_out; + return ret; +} + + +static int zlib_decompress_setup(struct crypto_pcomp *tfm, void *params, + unsigned int len) +{ + struct zlib_ctx *ctx = crypto_tfm_ctx(crypto_pcomp_tfm(tfm)); + struct z_stream_s *stream = &ctx->decomp_stream; + struct nlattr *tb[ZLIB_DECOMP_MAX + 1]; + int ret = 0; + + ret = nla_parse(tb, ZLIB_DECOMP_MAX, params, len, NULL); + if (ret) + return ret; + + zlib_decomp_exit(ctx); + + ctx->decomp_windowBits = tb[ZLIB_DECOMP_WINDOWBITS] + ? nla_get_u32(tb[ZLIB_DECOMP_WINDOWBITS]) + : DEF_WBITS; + + stream->workspace = vzalloc(zlib_inflate_workspacesize()); + if (!stream->workspace) + return -ENOMEM; + + ret = zlib_inflateInit2(stream, ctx->decomp_windowBits); + if (ret != Z_OK) { + vfree(stream->workspace); + stream->workspace = NULL; + return -EINVAL; + } + + return 0; +} + +static int zlib_decompress_init(struct crypto_pcomp *tfm) +{ + int ret; + struct zlib_ctx *dctx = crypto_tfm_ctx(crypto_pcomp_tfm(tfm)); + struct z_stream_s *stream = &dctx->decomp_stream; + + ret = zlib_inflateReset(stream); + if (ret != Z_OK) + return -EINVAL; + + return 0; +} + +static int zlib_decompress_update(struct crypto_pcomp *tfm, + struct comp_request *req) +{ + int ret; + struct zlib_ctx *dctx = crypto_tfm_ctx(crypto_pcomp_tfm(tfm)); + struct z_stream_s *stream = &dctx->decomp_stream; + + pr_debug("avail_in %u, avail_out %u\n", req->avail_in, req->avail_out); + stream->next_in = req->next_in; + stream->avail_in = req->avail_in; + stream->next_out = req->next_out; + stream->avail_out = req->avail_out; + + ret = zlib_inflate(stream, Z_SYNC_FLUSH); + switch (ret) { + case Z_OK: + case Z_STREAM_END: + break; + + case Z_BUF_ERROR: + pr_debug("zlib_inflate could not make progress\n"); + return -EAGAIN; + + default: + pr_debug("zlib_inflate failed %d\n", ret); + return -EINVAL; + } + + ret = req->avail_out - stream->avail_out; + pr_debug("avail_in %lu, avail_out %lu (consumed %lu, produced %u)\n", + stream->avail_in, stream->avail_out, + req->avail_in - stream->avail_in, ret); + req->next_in = stream->next_in; + req->avail_in = stream->avail_in; + req->next_out = stream->next_out; + req->avail_out = stream->avail_out; + return ret; +} + +static int zlib_decompress_final(struct crypto_pcomp *tfm, + struct comp_request *req) +{ + int ret; + struct zlib_ctx *dctx = crypto_tfm_ctx(crypto_pcomp_tfm(tfm)); + struct z_stream_s *stream = &dctx->decomp_stream; + + pr_debug("avail_in %u, avail_out %u\n", req->avail_in, req->avail_out); + stream->next_in = req->next_in; + stream->avail_in = req->avail_in; + stream->next_out = req->next_out; + stream->avail_out = req->avail_out; + + if (dctx->decomp_windowBits < 0) { + ret = zlib_inflate(stream, Z_SYNC_FLUSH); + /* + * Work around a bug in zlib, which sometimes wants to taste an + * extra byte when being used in the (undocumented) raw deflate + * mode. (From USAGI). + */ + if (ret == Z_OK && !stream->avail_in && stream->avail_out) { + const void *saved_next_in = stream->next_in; + u8 zerostuff = 0; + + stream->next_in = &zerostuff; + stream->avail_in = 1; + ret = zlib_inflate(stream, Z_FINISH); + stream->next_in = saved_next_in; + stream->avail_in = 0; + } + } else + ret = zlib_inflate(stream, Z_FINISH); + if (ret != Z_STREAM_END) { + pr_debug("zlib_inflate failed %d\n", ret); + return -EINVAL; + } + + ret = req->avail_out - stream->avail_out; + pr_debug("avail_in %lu, avail_out %lu (consumed %lu, produced %u)\n", + stream->avail_in, stream->avail_out, + req->avail_in - stream->avail_in, ret); + req->next_in = stream->next_in; + req->avail_in = stream->avail_in; + req->next_out = stream->next_out; + req->avail_out = stream->avail_out; + return ret; +} + + +static struct pcomp_alg zlib_alg = { + .compress_setup = zlib_compress_setup, + .compress_init = zlib_compress_init, + .compress_update = zlib_compress_update, + .compress_final = zlib_compress_final, + .decompress_setup = zlib_decompress_setup, + .decompress_init = zlib_decompress_init, + .decompress_update = zlib_decompress_update, + .decompress_final = zlib_decompress_final, + + .base = { + .cra_name = "zlib", + .cra_flags = CRYPTO_ALG_TYPE_PCOMPRESS, + .cra_ctxsize = sizeof(struct zlib_ctx), + .cra_module = THIS_MODULE, + .cra_init = zlib_init, + .cra_exit = zlib_exit, + } +}; + +static int __init zlib_mod_init(void) +{ + return crypto_register_pcomp(&zlib_alg); +} + +static void __exit zlib_mod_fini(void) +{ + crypto_unregister_pcomp(&zlib_alg); +} + +module_init(zlib_mod_init); +module_exit(zlib_mod_fini); + +MODULE_LICENSE("GPL"); +MODULE_DESCRIPTION("Zlib Compression Algorithm"); +MODULE_AUTHOR("Sony Corporation"); +MODULE_ALIAS_CRYPTO("zlib"); |