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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
36#define DEFLATE_DEF_LEVEL Z_DEFAULT_COMPRESSION
37#define DEFLATE_DEF_WINBITS 11
38#define DEFLATE_DEF_MEMLEVEL MAX_MEM_LEVEL
39
40struct deflate_ctx {
41 struct z_stream_s comp_stream;
42 struct z_stream_s decomp_stream;
43};
44
45static int deflate_comp_init(struct deflate_ctx *ctx)
46{
47 int ret = 0;
48 struct z_stream_s *stream = &ctx->comp_stream;
49
50 stream->workspace = vzalloc(zlib_deflate_workspacesize(
51 -DEFLATE_DEF_WINBITS, DEFLATE_DEF_MEMLEVEL));
52 if (!stream->workspace) {
53 ret = -ENOMEM;
54 goto out;
55 }
56 ret = zlib_deflateInit2(stream, DEFLATE_DEF_LEVEL, Z_DEFLATED,
57 -DEFLATE_DEF_WINBITS, DEFLATE_DEF_MEMLEVEL,
58 Z_DEFAULT_STRATEGY);
59 if (ret != Z_OK) {
60 ret = -EINVAL;
61 goto out_free;
62 }
63out:
64 return ret;
65out_free:
66 vfree(stream->workspace);
67 goto out;
68}
69
70static int deflate_decomp_init(struct deflate_ctx *ctx)
71{
72 int ret = 0;
73 struct z_stream_s *stream = &ctx->decomp_stream;
74
75 stream->workspace = vzalloc(zlib_inflate_workspacesize());
76 if (!stream->workspace) {
77 ret = -ENOMEM;
78 goto out;
79 }
80 ret = zlib_inflateInit2(stream, -DEFLATE_DEF_WINBITS);
81 if (ret != Z_OK) {
82 ret = -EINVAL;
83 goto out_free;
84 }
85out:
86 return ret;
87out_free:
88 vfree(stream->workspace);
89 goto out;
90}
91
92static void deflate_comp_exit(struct deflate_ctx *ctx)
93{
94 zlib_deflateEnd(&ctx->comp_stream);
95 vfree(ctx->comp_stream.workspace);
96}
97
98static void deflate_decomp_exit(struct deflate_ctx *ctx)
99{
100 zlib_inflateEnd(&ctx->decomp_stream);
101 vfree(ctx->decomp_stream.workspace);
102}
103
104static int deflate_init(struct crypto_tfm *tfm)
105{
106 struct deflate_ctx *ctx = crypto_tfm_ctx(tfm);
107 int ret;
108
109 ret = deflate_comp_init(ctx);
110 if (ret)
111 goto out;
112 ret = deflate_decomp_init(ctx);
113 if (ret)
114 deflate_comp_exit(ctx);
115out:
116 return ret;
117}
118
119static void deflate_exit(struct crypto_tfm *tfm)
120{
121 struct deflate_ctx *ctx = crypto_tfm_ctx(tfm);
122
123 deflate_comp_exit(ctx);
124 deflate_decomp_exit(ctx);
125}
126
127static int deflate_compress(struct crypto_tfm *tfm, const u8 *src,
128 unsigned int slen, u8 *dst, unsigned int *dlen)
129{
130 int ret = 0;
131 struct deflate_ctx *dctx = crypto_tfm_ctx(tfm);
132 struct z_stream_s *stream = &dctx->comp_stream;
133
134 ret = zlib_deflateReset(stream);
135 if (ret != Z_OK) {
136 ret = -EINVAL;
137 goto out;
138 }
139
140 stream->next_in = (u8 *)src;
141 stream->avail_in = slen;
142 stream->next_out = (u8 *)dst;
143 stream->avail_out = *dlen;
144
145 ret = zlib_deflate(stream, Z_FINISH);
146 if (ret != Z_STREAM_END) {
147 ret = -EINVAL;
148 goto out;
149 }
150 ret = 0;
151 *dlen = stream->total_out;
152out:
153 return ret;
154}
155
156static int deflate_decompress(struct crypto_tfm *tfm, const u8 *src,
157 unsigned int slen, u8 *dst, unsigned int *dlen)
158{
159
160 int ret = 0;
161 struct deflate_ctx *dctx = crypto_tfm_ctx(tfm);
162 struct z_stream_s *stream = &dctx->decomp_stream;
163
164 ret = zlib_inflateReset(stream);
165 if (ret != Z_OK) {
166 ret = -EINVAL;
167 goto out;
168 }
169
170 stream->next_in = (u8 *)src;
171 stream->avail_in = slen;
172 stream->next_out = (u8 *)dst;
173 stream->avail_out = *dlen;
174
175 ret = zlib_inflate(stream, Z_SYNC_FLUSH);
176 /*
177 * Work around a bug in zlib, which sometimes wants to taste an extra
178 * byte when being used in the (undocumented) raw deflate mode.
179 * (From USAGI).
180 */
181 if (ret == Z_OK && !stream->avail_in && stream->avail_out) {
182 u8 zerostuff = 0;
183 stream->next_in = &zerostuff;
184 stream->avail_in = 1;
185 ret = zlib_inflate(stream, Z_FINISH);
186 }
187 if (ret != Z_STREAM_END) {
188 ret = -EINVAL;
189 goto out;
190 }
191 ret = 0;
192 *dlen = stream->total_out;
193out:
194 return ret;
195}
196
197static struct crypto_alg alg = {
198 .cra_name = "deflate",
199 .cra_flags = CRYPTO_ALG_TYPE_COMPRESS,
200 .cra_ctxsize = sizeof(struct deflate_ctx),
201 .cra_module = THIS_MODULE,
202 .cra_init = deflate_init,
203 .cra_exit = deflate_exit,
204 .cra_u = { .compress = {
205 .coa_compress = deflate_compress,
206 .coa_decompress = deflate_decompress } }
207};
208
209static int __init deflate_mod_init(void)
210{
211 return crypto_register_alg(&alg);
212}
213
214static void __exit deflate_mod_fini(void)
215{
216 crypto_unregister_alg(&alg);
217}
218
219module_init(deflate_mod_init);
220module_exit(deflate_mod_fini);
221
222MODULE_LICENSE("GPL");
223MODULE_DESCRIPTION("Deflate Compression Algorithm for IPCOMP");
224MODULE_AUTHOR("James Morris <jmorris@intercode.com.au>");
225
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 <crypto/internal/scompress.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 = vzalloc(zlib_deflate_workspacesize(
52 -DEFLATE_DEF_WINBITS, DEFLATE_DEF_MEMLEVEL));
53 if (!stream->workspace) {
54 ret = -ENOMEM;
55 goto out;
56 }
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 = vzalloc(zlib_inflate_workspacesize());
77 if (!stream->workspace) {
78 ret = -ENOMEM;
79 goto out;
80 }
81 ret = zlib_inflateInit2(stream, -DEFLATE_DEF_WINBITS);
82 if (ret != Z_OK) {
83 ret = -EINVAL;
84 goto out_free;
85 }
86out:
87 return ret;
88out_free:
89 vfree(stream->workspace);
90 goto out;
91}
92
93static void deflate_comp_exit(struct deflate_ctx *ctx)
94{
95 zlib_deflateEnd(&ctx->comp_stream);
96 vfree(ctx->comp_stream.workspace);
97}
98
99static void deflate_decomp_exit(struct deflate_ctx *ctx)
100{
101 zlib_inflateEnd(&ctx->decomp_stream);
102 vfree(ctx->decomp_stream.workspace);
103}
104
105static int __deflate_init(void *ctx)
106{
107 int ret;
108
109 ret = deflate_comp_init(ctx);
110 if (ret)
111 goto out;
112 ret = deflate_decomp_init(ctx);
113 if (ret)
114 deflate_comp_exit(ctx);
115out:
116 return ret;
117}
118
119static void *deflate_alloc_ctx(struct crypto_scomp *tfm)
120{
121 struct deflate_ctx *ctx;
122 int ret;
123
124 ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
125 if (!ctx)
126 return ERR_PTR(-ENOMEM);
127
128 ret = __deflate_init(ctx);
129 if (ret) {
130 kfree(ctx);
131 return ERR_PTR(ret);
132 }
133
134 return ctx;
135}
136
137static int deflate_init(struct crypto_tfm *tfm)
138{
139 struct deflate_ctx *ctx = crypto_tfm_ctx(tfm);
140
141 return __deflate_init(ctx);
142}
143
144static void __deflate_exit(void *ctx)
145{
146 deflate_comp_exit(ctx);
147 deflate_decomp_exit(ctx);
148}
149
150static void deflate_free_ctx(struct crypto_scomp *tfm, void *ctx)
151{
152 __deflate_exit(ctx);
153 kzfree(ctx);
154}
155
156static void deflate_exit(struct crypto_tfm *tfm)
157{
158 struct deflate_ctx *ctx = crypto_tfm_ctx(tfm);
159
160 __deflate_exit(ctx);
161}
162
163static int __deflate_compress(const u8 *src, unsigned int slen,
164 u8 *dst, unsigned int *dlen, void *ctx)
165{
166 int ret = 0;
167 struct deflate_ctx *dctx = ctx;
168 struct z_stream_s *stream = &dctx->comp_stream;
169
170 ret = zlib_deflateReset(stream);
171 if (ret != Z_OK) {
172 ret = -EINVAL;
173 goto out;
174 }
175
176 stream->next_in = (u8 *)src;
177 stream->avail_in = slen;
178 stream->next_out = (u8 *)dst;
179 stream->avail_out = *dlen;
180
181 ret = zlib_deflate(stream, Z_FINISH);
182 if (ret != Z_STREAM_END) {
183 ret = -EINVAL;
184 goto out;
185 }
186 ret = 0;
187 *dlen = stream->total_out;
188out:
189 return ret;
190}
191
192static int deflate_compress(struct crypto_tfm *tfm, const u8 *src,
193 unsigned int slen, u8 *dst, unsigned int *dlen)
194{
195 struct deflate_ctx *dctx = crypto_tfm_ctx(tfm);
196
197 return __deflate_compress(src, slen, dst, dlen, dctx);
198}
199
200static int deflate_scompress(struct crypto_scomp *tfm, const u8 *src,
201 unsigned int slen, u8 *dst, unsigned int *dlen,
202 void *ctx)
203{
204 return __deflate_compress(src, slen, dst, dlen, ctx);
205}
206
207static int __deflate_decompress(const u8 *src, unsigned int slen,
208 u8 *dst, unsigned int *dlen, void *ctx)
209{
210
211 int ret = 0;
212 struct deflate_ctx *dctx = ctx;
213 struct z_stream_s *stream = &dctx->decomp_stream;
214
215 ret = zlib_inflateReset(stream);
216 if (ret != Z_OK) {
217 ret = -EINVAL;
218 goto out;
219 }
220
221 stream->next_in = (u8 *)src;
222 stream->avail_in = slen;
223 stream->next_out = (u8 *)dst;
224 stream->avail_out = *dlen;
225
226 ret = zlib_inflate(stream, Z_SYNC_FLUSH);
227 /*
228 * Work around a bug in zlib, which sometimes wants to taste an extra
229 * byte when being used in the (undocumented) raw deflate mode.
230 * (From USAGI).
231 */
232 if (ret == Z_OK && !stream->avail_in && stream->avail_out) {
233 u8 zerostuff = 0;
234 stream->next_in = &zerostuff;
235 stream->avail_in = 1;
236 ret = zlib_inflate(stream, Z_FINISH);
237 }
238 if (ret != Z_STREAM_END) {
239 ret = -EINVAL;
240 goto out;
241 }
242 ret = 0;
243 *dlen = stream->total_out;
244out:
245 return ret;
246}
247
248static int deflate_decompress(struct crypto_tfm *tfm, const u8 *src,
249 unsigned int slen, u8 *dst, unsigned int *dlen)
250{
251 struct deflate_ctx *dctx = crypto_tfm_ctx(tfm);
252
253 return __deflate_decompress(src, slen, dst, dlen, dctx);
254}
255
256static int deflate_sdecompress(struct crypto_scomp *tfm, const u8 *src,
257 unsigned int slen, u8 *dst, unsigned int *dlen,
258 void *ctx)
259{
260 return __deflate_decompress(src, slen, dst, dlen, ctx);
261}
262
263static struct crypto_alg alg = {
264 .cra_name = "deflate",
265 .cra_flags = CRYPTO_ALG_TYPE_COMPRESS,
266 .cra_ctxsize = sizeof(struct deflate_ctx),
267 .cra_module = THIS_MODULE,
268 .cra_init = deflate_init,
269 .cra_exit = deflate_exit,
270 .cra_u = { .compress = {
271 .coa_compress = deflate_compress,
272 .coa_decompress = deflate_decompress } }
273};
274
275static struct scomp_alg scomp = {
276 .alloc_ctx = deflate_alloc_ctx,
277 .free_ctx = deflate_free_ctx,
278 .compress = deflate_scompress,
279 .decompress = deflate_sdecompress,
280 .base = {
281 .cra_name = "deflate",
282 .cra_driver_name = "deflate-scomp",
283 .cra_module = THIS_MODULE,
284 }
285};
286
287static int __init deflate_mod_init(void)
288{
289 int ret;
290
291 ret = crypto_register_alg(&alg);
292 if (ret)
293 return ret;
294
295 ret = crypto_register_scomp(&scomp);
296 if (ret) {
297 crypto_unregister_alg(&alg);
298 return ret;
299 }
300
301 return ret;
302}
303
304static void __exit deflate_mod_fini(void)
305{
306 crypto_unregister_alg(&alg);
307 crypto_unregister_scomp(&scomp);
308}
309
310module_init(deflate_mod_init);
311module_exit(deflate_mod_fini);
312
313MODULE_LICENSE("GPL");
314MODULE_DESCRIPTION("Deflate Compression Algorithm for IPCOMP");
315MODULE_AUTHOR("James Morris <jmorris@intercode.com.au>");
316MODULE_ALIAS_CRYPTO("deflate");