]> git.proxmox.com Git - mirror_ubuntu-bionic-kernel.git/blob - crypto/deflate.c
Merge tag 'metag-for-v4.11-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git...
[mirror_ubuntu-bionic-kernel.git] / crypto / deflate.c
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
41 struct deflate_ctx {
42 struct z_stream_s comp_stream;
43 struct z_stream_s decomp_stream;
44 };
45
46 static 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 }
64 out:
65 return ret;
66 out_free:
67 vfree(stream->workspace);
68 goto out;
69 }
70
71 static 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 }
86 out:
87 return ret;
88 out_free:
89 vfree(stream->workspace);
90 goto out;
91 }
92
93 static void deflate_comp_exit(struct deflate_ctx *ctx)
94 {
95 zlib_deflateEnd(&ctx->comp_stream);
96 vfree(ctx->comp_stream.workspace);
97 }
98
99 static void deflate_decomp_exit(struct deflate_ctx *ctx)
100 {
101 zlib_inflateEnd(&ctx->decomp_stream);
102 vfree(ctx->decomp_stream.workspace);
103 }
104
105 static 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);
115 out:
116 return ret;
117 }
118
119 static 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
137 static 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
144 static void __deflate_exit(void *ctx)
145 {
146 deflate_comp_exit(ctx);
147 deflate_decomp_exit(ctx);
148 }
149
150 static void deflate_free_ctx(struct crypto_scomp *tfm, void *ctx)
151 {
152 __deflate_exit(ctx);
153 kzfree(ctx);
154 }
155
156 static void deflate_exit(struct crypto_tfm *tfm)
157 {
158 struct deflate_ctx *ctx = crypto_tfm_ctx(tfm);
159
160 __deflate_exit(ctx);
161 }
162
163 static 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;
188 out:
189 return ret;
190 }
191
192 static 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
200 static 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
207 static 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;
244 out:
245 return ret;
246 }
247
248 static 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
256 static 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
263 static 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
275 static 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
287 static 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
304 static void __exit deflate_mod_fini(void)
305 {
306 crypto_unregister_alg(&alg);
307 crypto_unregister_scomp(&scomp);
308 }
309
310 module_init(deflate_mod_init);
311 module_exit(deflate_mod_fini);
312
313 MODULE_LICENSE("GPL");
314 MODULE_DESCRIPTION("Deflate Compression Algorithm for IPCOMP");
315 MODULE_AUTHOR("James Morris <jmorris@intercode.com.au>");
316 MODULE_ALIAS_CRYPTO("deflate");