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authorLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 18:20:36 -0400
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 18:20:36 -0400
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 000000000000..77d7655d316a
--- /dev/null
+++ b/crypto/deflate.c
@@ -0,0 +1,223 @@
1/*
2 * Cryptographic API.
3 *
4 * Deflate algorithm (RFC 1951), implemented here primarily for use
5 * by IPCOMP (RFC 3173 & RFC 2394).
6 *
7 * Copyright (c) 2003 James Morris <jmorris@intercode.com.au>
8 *
9 * This program is free software; you can redistribute it and/or modify it
10 * under the terms of the GNU General Public License as published by the Free
11 * Software Foundation; either version 2 of the License, or (at your option)
12 * any later version.
13 *
14 * FIXME: deflate transforms will require up to a total of about 436k of kernel
15 * memory on i386 (390k for compression, the rest for decompression), as the
16 * current zlib kernel code uses a worst case pre-allocation system by default.
17 * This needs to be fixed so that the amount of memory required is properly
18 * related to the winbits and memlevel parameters.
19 *
20 * The default winbits of 11 should suit most packets, and it may be something
21 * to configure on a per-tfm basis in the future.
22 *
23 * Currently, compression history is not maintained between tfm calls, as
24 * it is not needed for IPCOMP and keeps the code simpler. It can be
25 * implemented if someone wants it.
26 */
27#include <linux/init.h>
28#include <linux/module.h>
29#include <linux/crypto.h>
30#include <linux/zlib.h>
31#include <linux/vmalloc.h>
32#include <linux/interrupt.h>
33#include <linux/mm.h>
34#include <linux/net.h>
35#include <linux/slab.h>
36
37#define DEFLATE_DEF_LEVEL Z_DEFAULT_COMPRESSION
38#define DEFLATE_DEF_WINBITS 11
39#define DEFLATE_DEF_MEMLEVEL MAX_MEM_LEVEL
40
41struct deflate_ctx {
42 struct z_stream_s comp_stream;
43 struct z_stream_s decomp_stream;
44};
45
46static int deflate_comp_init(struct deflate_ctx *ctx)
47{
48 int ret = 0;
49 struct z_stream_s *stream = &ctx->comp_stream;
50
51 stream->workspace = vmalloc(zlib_deflate_workspacesize());
52 if (!stream->workspace ) {
53 ret = -ENOMEM;
54 goto out;
55 }
56 memset(stream->workspace, 0, zlib_deflate_workspacesize());
57 ret = zlib_deflateInit2(stream, DEFLATE_DEF_LEVEL, Z_DEFLATED,
58 -DEFLATE_DEF_WINBITS, DEFLATE_DEF_MEMLEVEL,
59 Z_DEFAULT_STRATEGY);
60 if (ret != Z_OK) {
61 ret = -EINVAL;
62 goto out_free;
63 }
64out:
65 return ret;
66out_free:
67 vfree(stream->workspace);
68 goto out;
69}
70
71static int deflate_decomp_init(struct deflate_ctx *ctx)
72{
73 int ret = 0;
74 struct z_stream_s *stream = &ctx->decomp_stream;
75
76 stream->workspace = kmalloc(zlib_inflate_workspacesize(), GFP_KERNEL);
77 if (!stream->workspace ) {
78 ret = -ENOMEM;
79 goto out;
80 }
81 memset(stream->workspace, 0, zlib_inflate_workspacesize());
82 ret = zlib_inflateInit2(stream, -DEFLATE_DEF_WINBITS);
83 if (ret != Z_OK) {
84 ret = -EINVAL;
85 goto out_free;
86 }
87out:
88 return ret;
89out_free:
90 kfree(stream->workspace);
91 goto out;
92}
93
94static void deflate_comp_exit(struct deflate_ctx *ctx)
95{
96 vfree(ctx->comp_stream.workspace);
97}
98
99static void deflate_decomp_exit(struct deflate_ctx *ctx)
100{
101 kfree(ctx->decomp_stream.workspace);
102}
103
104static int deflate_init(void *ctx)
105{
106 int ret;
107
108 ret = deflate_comp_init(ctx);
109 if (ret)
110 goto out;
111 ret = deflate_decomp_init(ctx);
112 if (ret)
113 deflate_comp_exit(ctx);
114out:
115 return ret;
116}
117
118static void deflate_exit(void *ctx)
119{
120 deflate_comp_exit(ctx);
121 deflate_decomp_exit(ctx);
122}
123
124static int deflate_compress(void *ctx, const u8 *src, unsigned int slen,
125 u8 *dst, unsigned int *dlen)
126{
127 int ret = 0;
128 struct deflate_ctx *dctx = ctx;
129 struct z_stream_s *stream = &dctx->comp_stream;
130
131 ret = zlib_deflateReset(stream);
132 if (ret != Z_OK) {
133 ret = -EINVAL;
134 goto out;
135 }
136
137 stream->next_in = (u8 *)src;
138 stream->avail_in = slen;
139 stream->next_out = (u8 *)dst;
140 stream->avail_out = *dlen;
141
142 ret = zlib_deflate(stream, Z_FINISH);
143 if (ret != Z_STREAM_END) {
144 ret = -EINVAL;
145 goto out;
146 }
147 ret = 0;
148 *dlen = stream->total_out;
149out:
150 return ret;
151}
152
153static int deflate_decompress(void *ctx, const u8 *src, unsigned int slen,
154 u8 *dst, unsigned int *dlen)
155{
156
157 int ret = 0;
158 struct deflate_ctx *dctx = ctx;
159 struct z_stream_s *stream = &dctx->decomp_stream;
160
161 ret = zlib_inflateReset(stream);
162 if (ret != Z_OK) {
163 ret = -EINVAL;
164 goto out;
165 }
166
167 stream->next_in = (u8 *)src;
168 stream->avail_in = slen;
169 stream->next_out = (u8 *)dst;
170 stream->avail_out = *dlen;
171
172 ret = zlib_inflate(stream, Z_SYNC_FLUSH);
173 /*
174 * Work around a bug in zlib, which sometimes wants to taste an extra
175 * byte when being used in the (undocumented) raw deflate mode.
176 * (From USAGI).
177 */
178 if (ret == Z_OK && !stream->avail_in && stream->avail_out) {
179 u8 zerostuff = 0;
180 stream->next_in = &zerostuff;
181 stream->avail_in = 1;
182 ret = zlib_inflate(stream, Z_FINISH);
183 }
184 if (ret != Z_STREAM_END) {
185 ret = -EINVAL;
186 goto out;
187 }
188 ret = 0;
189 *dlen = stream->total_out;
190out:
191 return ret;
192}
193
194static struct crypto_alg alg = {
195 .cra_name = "deflate",
196 .cra_flags = CRYPTO_ALG_TYPE_COMPRESS,
197 .cra_ctxsize = sizeof(struct deflate_ctx),
198 .cra_module = THIS_MODULE,
199 .cra_list = LIST_HEAD_INIT(alg.cra_list),
200 .cra_u = { .compress = {
201 .coa_init = deflate_init,
202 .coa_exit = deflate_exit,
203 .coa_compress = deflate_compress,
204 .coa_decompress = deflate_decompress } }
205};
206
207static int __init init(void)
208{
209 return crypto_register_alg(&alg);
210}
211
212static void __exit fini(void)
213{
214 crypto_unregister_alg(&alg);
215}
216
217module_init(init);
218module_exit(fini);
219
220MODULE_LICENSE("GPL");
221MODULE_DESCRIPTION("Deflate Compression Algorithm for IPCOMP");
222MODULE_AUTHOR("James Morris <jmorris@intercode.com.au>");
223