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authorLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 22:20:36 (GMT)
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 22:20:36 (GMT)
commit1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch)
tree0bba044c4ce775e45a88a51686b5d9f90697ea9d /crypto/deflate.c
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
Diffstat (limited to 'crypto/deflate.c')
-rw-r--r--crypto/deflate.c223
1 files changed, 223 insertions, 0 deletions
diff --git a/crypto/deflate.c b/crypto/deflate.c
new file mode 100644
index 0000000..77d7655
--- /dev/null
+++ b/crypto/deflate.c
@@ -0,0 +1,223 @@
+/*
+ * 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>
+ *
+ * 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.
+ *
+ * The default winbits of 11 should suit most packets, and it may be something
+ * to configure on a per-tfm basis in the future.
+ *
+ * Currently, compression history is not maintained between tfm calls, as
+ * it is not needed for IPCOMP and keeps the code simpler. It can be
+ * implemented if someone wants it.
+ */
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/crypto.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>
+
+#define DEFLATE_DEF_LEVEL Z_DEFAULT_COMPRESSION
+#define DEFLATE_DEF_WINBITS 11
+#define DEFLATE_DEF_MEMLEVEL MAX_MEM_LEVEL
+
+struct deflate_ctx {
+ struct z_stream_s comp_stream;
+ struct z_stream_s decomp_stream;
+};
+
+static int deflate_comp_init(struct deflate_ctx *ctx)
+{
+ int ret = 0;
+ struct z_stream_s *stream = &ctx->comp_stream;
+
+ stream->workspace = vmalloc(zlib_deflate_workspacesize());
+ if (!stream->workspace ) {
+ ret = -ENOMEM;
+ goto out;
+ }
+ memset(stream->workspace, 0, zlib_deflate_workspacesize());
+ ret = zlib_deflateInit2(stream, DEFLATE_DEF_LEVEL, Z_DEFLATED,
+ -DEFLATE_DEF_WINBITS, DEFLATE_DEF_MEMLEVEL,
+ Z_DEFAULT_STRATEGY);
+ if (ret != Z_OK) {
+ ret = -EINVAL;
+ goto out_free;
+ }
+out:
+ return ret;
+out_free:
+ vfree(stream->workspace);
+ goto out;
+}
+
+static int deflate_decomp_init(struct deflate_ctx *ctx)
+{
+ int ret = 0;
+ struct z_stream_s *stream = &ctx->decomp_stream;
+
+ stream->workspace = kmalloc(zlib_inflate_workspacesize(), GFP_KERNEL);
+ if (!stream->workspace ) {
+ ret = -ENOMEM;
+ goto out;
+ }
+ memset(stream->workspace, 0, zlib_inflate_workspacesize());
+ ret = zlib_inflateInit2(stream, -DEFLATE_DEF_WINBITS);
+ if (ret != Z_OK) {
+ ret = -EINVAL;
+ goto out_free;
+ }
+out:
+ return ret;
+out_free:
+ kfree(stream->workspace);
+ goto out;
+}
+
+static void deflate_comp_exit(struct deflate_ctx *ctx)
+{
+ vfree(ctx->comp_stream.workspace);
+}
+
+static void deflate_decomp_exit(struct deflate_ctx *ctx)
+{
+ kfree(ctx->decomp_stream.workspace);
+}
+
+static int deflate_init(void *ctx)
+{
+ int ret;
+
+ ret = deflate_comp_init(ctx);
+ if (ret)
+ goto out;
+ ret = deflate_decomp_init(ctx);
+ if (ret)
+ deflate_comp_exit(ctx);
+out:
+ return ret;
+}
+
+static void deflate_exit(void *ctx)
+{
+ deflate_comp_exit(ctx);
+ deflate_decomp_exit(ctx);
+}
+
+static int deflate_compress(void *ctx, const u8 *src, unsigned int slen,
+ u8 *dst, unsigned int *dlen)
+{
+ int ret = 0;
+ struct deflate_ctx *dctx = ctx;
+ struct z_stream_s *stream = &dctx->comp_stream;
+
+ ret = zlib_deflateReset(stream);
+ if (ret != Z_OK) {
+ ret = -EINVAL;
+ goto out;
+ }
+
+ stream->next_in = (u8 *)src;
+ stream->avail_in = slen;
+ stream->next_out = (u8 *)dst;
+ stream->avail_out = *dlen;
+
+ ret = zlib_deflate(stream, Z_FINISH);
+ if (ret != Z_STREAM_END) {
+ ret = -EINVAL;
+ goto out;
+ }
+ ret = 0;
+ *dlen = stream->total_out;
+out:
+ return ret;
+}
+
+static int deflate_decompress(void *ctx, const u8 *src, unsigned int slen,
+ u8 *dst, unsigned int *dlen)
+{
+
+ int ret = 0;
+ struct deflate_ctx *dctx = ctx;
+ struct z_stream_s *stream = &dctx->decomp_stream;
+
+ ret = zlib_inflateReset(stream);
+ if (ret != Z_OK) {
+ ret = -EINVAL;
+ goto out;
+ }
+
+ stream->next_in = (u8 *)src;
+ stream->avail_in = slen;
+ stream->next_out = (u8 *)dst;
+ stream->avail_out = *dlen;
+
+ 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) {
+ u8 zerostuff = 0;
+ stream->next_in = &zerostuff;
+ stream->avail_in = 1;
+ ret = zlib_inflate(stream, Z_FINISH);
+ }
+ if (ret != Z_STREAM_END) {
+ ret = -EINVAL;
+ goto out;
+ }
+ ret = 0;
+ *dlen = stream->total_out;
+out:
+ return ret;
+}
+
+static struct crypto_alg alg = {
+ .cra_name = "deflate",
+ .cra_flags = CRYPTO_ALG_TYPE_COMPRESS,
+ .cra_ctxsize = sizeof(struct deflate_ctx),
+ .cra_module = THIS_MODULE,
+ .cra_list = LIST_HEAD_INIT(alg.cra_list),
+ .cra_u = { .compress = {
+ .coa_init = deflate_init,
+ .coa_exit = deflate_exit,
+ .coa_compress = deflate_compress,
+ .coa_decompress = deflate_decompress } }
+};
+
+static int __init init(void)
+{
+ return crypto_register_alg(&alg);
+}
+
+static void __exit fini(void)
+{
+ crypto_unregister_alg(&alg);
+}
+
+module_init(init);
+module_exit(fini);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("Deflate Compression Algorithm for IPCOMP");
+MODULE_AUTHOR("James Morris <jmorris@intercode.com.au>");
+

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