/* * 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 <linux/slab.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); kfree(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]; size_t workspacesize; int ret; ret = nla_parse(tb, ZLIB_COMP_MAX, params, len, NULL); if (ret) return ret; zlib_comp_exit(ctx); workspacesize = zlib_deflate_workspacesize(); stream->workspace = vmalloc(workspacesize); if (!stream->workspace) return -ENOMEM; memset(stream->workspace, 0, workspacesize); 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, tb[ZLIB_COMP_WINDOWBITS] ? nla_get_u32(tb[ZLIB_COMP_WINDOWBITS]) : MAX_WBITS, tb[ZLIB_COMP_MEMLEVEL] ? nla_get_u32(tb[ZLIB_COMP_MEMLEVEL]) : DEF_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 %u, avail_out %u (consumed %u, 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 %u, avail_out %u (consumed %u, 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 = kzalloc(zlib_inflate_workspacesize(), GFP_KERNEL); if (!stream->workspace) return -ENOMEM; ret = zlib_inflateInit2(stream, ctx->decomp_windowBits); if (ret != Z_OK) { kfree(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 %u, avail_out %u (consumed %u, 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 %u, avail_out %u (consumed %u, 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");