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1 | /* | |
2 | * Cryptographic API. | |
3 | * | |
4 | * Zlib algorithm | |
5 | * | |
6 | * Copyright 2008 Sony Corporation | |
7 | * | |
8 | * Based on deflate.c, which is | |
9 | * Copyright (c) 2003 James Morris <jmorris@intercode.com.au> | |
10 | * | |
11 | * This program is free software; you can redistribute it and/or modify it | |
12 | * under the terms of the GNU General Public License as published by the Free | |
13 | * Software Foundation; either version 2 of the License, or (at your option) | |
14 | * any later version. | |
15 | * | |
16 | * FIXME: deflate transforms will require up to a total of about 436k of kernel | |
17 | * memory on i386 (390k for compression, the rest for decompression), as the | |
18 | * current zlib kernel code uses a worst case pre-allocation system by default. | |
19 | * This needs to be fixed so that the amount of memory required is properly | |
20 | * related to the winbits and memlevel parameters. | |
21 | */ | |
22 | ||
23 | #define pr_fmt(fmt) "%s: " fmt, __func__ | |
24 | ||
25 | #include <linux/init.h> | |
26 | #include <linux/module.h> | |
27 | #include <linux/zlib.h> | |
28 | #include <linux/vmalloc.h> | |
29 | #include <linux/interrupt.h> | |
30 | #include <linux/mm.h> | |
31 | #include <linux/net.h> | |
32 | #include <linux/slab.h> | |
33 | ||
34 | #include <crypto/internal/compress.h> | |
35 | ||
36 | #include <net/netlink.h> | |
37 | ||
38 | ||
39 | struct zlib_ctx { | |
40 | struct z_stream_s comp_stream; | |
41 | struct z_stream_s decomp_stream; | |
42 | int decomp_windowBits; | |
43 | }; | |
44 | ||
45 | ||
46 | static void zlib_comp_exit(struct zlib_ctx *ctx) | |
47 | { | |
48 | struct z_stream_s *stream = &ctx->comp_stream; | |
49 | ||
50 | if (stream->workspace) { | |
51 | zlib_deflateEnd(stream); | |
52 | vfree(stream->workspace); | |
53 | stream->workspace = NULL; | |
54 | } | |
55 | } | |
56 | ||
57 | static void zlib_decomp_exit(struct zlib_ctx *ctx) | |
58 | { | |
59 | struct z_stream_s *stream = &ctx->decomp_stream; | |
60 | ||
61 | if (stream->workspace) { | |
62 | zlib_inflateEnd(stream); | |
63 | kfree(stream->workspace); | |
64 | stream->workspace = NULL; | |
65 | } | |
66 | } | |
67 | ||
68 | static int zlib_init(struct crypto_tfm *tfm) | |
69 | { | |
70 | return 0; | |
71 | } | |
72 | ||
73 | static void zlib_exit(struct crypto_tfm *tfm) | |
74 | { | |
75 | struct zlib_ctx *ctx = crypto_tfm_ctx(tfm); | |
76 | ||
77 | zlib_comp_exit(ctx); | |
78 | zlib_decomp_exit(ctx); | |
79 | } | |
80 | ||
81 | ||
82 | static int zlib_compress_setup(struct crypto_pcomp *tfm, void *params, | |
83 | unsigned int len) | |
84 | { | |
85 | struct zlib_ctx *ctx = crypto_tfm_ctx(crypto_pcomp_tfm(tfm)); | |
86 | struct z_stream_s *stream = &ctx->comp_stream; | |
87 | struct nlattr *tb[ZLIB_COMP_MAX + 1]; | |
88 | int window_bits, mem_level; | |
89 | size_t workspacesize; | |
90 | int ret; | |
91 | ||
92 | ret = nla_parse(tb, ZLIB_COMP_MAX, params, len, NULL); | |
93 | if (ret) | |
94 | return ret; | |
95 | ||
96 | zlib_comp_exit(ctx); | |
97 | ||
98 | window_bits = tb[ZLIB_COMP_WINDOWBITS] | |
99 | ? nla_get_u32(tb[ZLIB_COMP_WINDOWBITS]) | |
100 | : MAX_WBITS; | |
101 | mem_level = tb[ZLIB_COMP_MEMLEVEL] | |
102 | ? nla_get_u32(tb[ZLIB_COMP_MEMLEVEL]) | |
103 | : DEF_MEM_LEVEL; | |
104 | ||
105 | workspacesize = zlib_deflate_workspacesize(window_bits, mem_level); | |
106 | stream->workspace = vzalloc(workspacesize); | |
107 | if (!stream->workspace) | |
108 | return -ENOMEM; | |
109 | ||
110 | ret = zlib_deflateInit2(stream, | |
111 | tb[ZLIB_COMP_LEVEL] | |
112 | ? nla_get_u32(tb[ZLIB_COMP_LEVEL]) | |
113 | : Z_DEFAULT_COMPRESSION, | |
114 | tb[ZLIB_COMP_METHOD] | |
115 | ? nla_get_u32(tb[ZLIB_COMP_METHOD]) | |
116 | : Z_DEFLATED, | |
117 | window_bits, | |
118 | mem_level, | |
119 | tb[ZLIB_COMP_STRATEGY] | |
120 | ? nla_get_u32(tb[ZLIB_COMP_STRATEGY]) | |
121 | : Z_DEFAULT_STRATEGY); | |
122 | if (ret != Z_OK) { | |
123 | vfree(stream->workspace); | |
124 | stream->workspace = NULL; | |
125 | return -EINVAL; | |
126 | } | |
127 | ||
128 | return 0; | |
129 | } | |
130 | ||
131 | static int zlib_compress_init(struct crypto_pcomp *tfm) | |
132 | { | |
133 | int ret; | |
134 | struct zlib_ctx *dctx = crypto_tfm_ctx(crypto_pcomp_tfm(tfm)); | |
135 | struct z_stream_s *stream = &dctx->comp_stream; | |
136 | ||
137 | ret = zlib_deflateReset(stream); | |
138 | if (ret != Z_OK) | |
139 | return -EINVAL; | |
140 | ||
141 | return 0; | |
142 | } | |
143 | ||
144 | static int zlib_compress_update(struct crypto_pcomp *tfm, | |
145 | struct comp_request *req) | |
146 | { | |
147 | int ret; | |
148 | struct zlib_ctx *dctx = crypto_tfm_ctx(crypto_pcomp_tfm(tfm)); | |
149 | struct z_stream_s *stream = &dctx->comp_stream; | |
150 | ||
151 | pr_debug("avail_in %u, avail_out %u\n", req->avail_in, req->avail_out); | |
152 | stream->next_in = req->next_in; | |
153 | stream->avail_in = req->avail_in; | |
154 | stream->next_out = req->next_out; | |
155 | stream->avail_out = req->avail_out; | |
156 | ||
157 | ret = zlib_deflate(stream, Z_NO_FLUSH); | |
158 | switch (ret) { | |
159 | case Z_OK: | |
160 | break; | |
161 | ||
162 | case Z_BUF_ERROR: | |
163 | pr_debug("zlib_deflate could not make progress\n"); | |
164 | return -EAGAIN; | |
165 | ||
166 | default: | |
167 | pr_debug("zlib_deflate failed %d\n", ret); | |
168 | return -EINVAL; | |
169 | } | |
170 | ||
171 | ret = req->avail_out - stream->avail_out; | |
172 | pr_debug("avail_in %u, avail_out %u (consumed %u, produced %u)\n", | |
173 | stream->avail_in, stream->avail_out, | |
174 | req->avail_in - stream->avail_in, ret); | |
175 | req->next_in = stream->next_in; | |
176 | req->avail_in = stream->avail_in; | |
177 | req->next_out = stream->next_out; | |
178 | req->avail_out = stream->avail_out; | |
179 | return ret; | |
180 | } | |
181 | ||
182 | static int zlib_compress_final(struct crypto_pcomp *tfm, | |
183 | struct comp_request *req) | |
184 | { | |
185 | int ret; | |
186 | struct zlib_ctx *dctx = crypto_tfm_ctx(crypto_pcomp_tfm(tfm)); | |
187 | struct z_stream_s *stream = &dctx->comp_stream; | |
188 | ||
189 | pr_debug("avail_in %u, avail_out %u\n", req->avail_in, req->avail_out); | |
190 | stream->next_in = req->next_in; | |
191 | stream->avail_in = req->avail_in; | |
192 | stream->next_out = req->next_out; | |
193 | stream->avail_out = req->avail_out; | |
194 | ||
195 | ret = zlib_deflate(stream, Z_FINISH); | |
196 | if (ret != Z_STREAM_END) { | |
197 | pr_debug("zlib_deflate failed %d\n", ret); | |
198 | return -EINVAL; | |
199 | } | |
200 | ||
201 | ret = req->avail_out - stream->avail_out; | |
202 | pr_debug("avail_in %u, avail_out %u (consumed %u, produced %u)\n", | |
203 | stream->avail_in, stream->avail_out, | |
204 | req->avail_in - stream->avail_in, ret); | |
205 | req->next_in = stream->next_in; | |
206 | req->avail_in = stream->avail_in; | |
207 | req->next_out = stream->next_out; | |
208 | req->avail_out = stream->avail_out; | |
209 | return ret; | |
210 | } | |
211 | ||
212 | ||
213 | static int zlib_decompress_setup(struct crypto_pcomp *tfm, void *params, | |
214 | unsigned int len) | |
215 | { | |
216 | struct zlib_ctx *ctx = crypto_tfm_ctx(crypto_pcomp_tfm(tfm)); | |
217 | struct z_stream_s *stream = &ctx->decomp_stream; | |
218 | struct nlattr *tb[ZLIB_DECOMP_MAX + 1]; | |
219 | int ret = 0; | |
220 | ||
221 | ret = nla_parse(tb, ZLIB_DECOMP_MAX, params, len, NULL); | |
222 | if (ret) | |
223 | return ret; | |
224 | ||
225 | zlib_decomp_exit(ctx); | |
226 | ||
227 | ctx->decomp_windowBits = tb[ZLIB_DECOMP_WINDOWBITS] | |
228 | ? nla_get_u32(tb[ZLIB_DECOMP_WINDOWBITS]) | |
229 | : DEF_WBITS; | |
230 | ||
231 | stream->workspace = kzalloc(zlib_inflate_workspacesize(), GFP_KERNEL); | |
232 | if (!stream->workspace) | |
233 | return -ENOMEM; | |
234 | ||
235 | ret = zlib_inflateInit2(stream, ctx->decomp_windowBits); | |
236 | if (ret != Z_OK) { | |
237 | kfree(stream->workspace); | |
238 | stream->workspace = NULL; | |
239 | return -EINVAL; | |
240 | } | |
241 | ||
242 | return 0; | |
243 | } | |
244 | ||
245 | static int zlib_decompress_init(struct crypto_pcomp *tfm) | |
246 | { | |
247 | int ret; | |
248 | struct zlib_ctx *dctx = crypto_tfm_ctx(crypto_pcomp_tfm(tfm)); | |
249 | struct z_stream_s *stream = &dctx->decomp_stream; | |
250 | ||
251 | ret = zlib_inflateReset(stream); | |
252 | if (ret != Z_OK) | |
253 | return -EINVAL; | |
254 | ||
255 | return 0; | |
256 | } | |
257 | ||
258 | static int zlib_decompress_update(struct crypto_pcomp *tfm, | |
259 | struct comp_request *req) | |
260 | { | |
261 | int ret; | |
262 | struct zlib_ctx *dctx = crypto_tfm_ctx(crypto_pcomp_tfm(tfm)); | |
263 | struct z_stream_s *stream = &dctx->decomp_stream; | |
264 | ||
265 | pr_debug("avail_in %u, avail_out %u\n", req->avail_in, req->avail_out); | |
266 | stream->next_in = req->next_in; | |
267 | stream->avail_in = req->avail_in; | |
268 | stream->next_out = req->next_out; | |
269 | stream->avail_out = req->avail_out; | |
270 | ||
271 | ret = zlib_inflate(stream, Z_SYNC_FLUSH); | |
272 | switch (ret) { | |
273 | case Z_OK: | |
274 | case Z_STREAM_END: | |
275 | break; | |
276 | ||
277 | case Z_BUF_ERROR: | |
278 | pr_debug("zlib_inflate could not make progress\n"); | |
279 | return -EAGAIN; | |
280 | ||
281 | default: | |
282 | pr_debug("zlib_inflate failed %d\n", ret); | |
283 | return -EINVAL; | |
284 | } | |
285 | ||
286 | ret = req->avail_out - stream->avail_out; | |
287 | pr_debug("avail_in %u, avail_out %u (consumed %u, produced %u)\n", | |
288 | stream->avail_in, stream->avail_out, | |
289 | req->avail_in - stream->avail_in, ret); | |
290 | req->next_in = stream->next_in; | |
291 | req->avail_in = stream->avail_in; | |
292 | req->next_out = stream->next_out; | |
293 | req->avail_out = stream->avail_out; | |
294 | return ret; | |
295 | } | |
296 | ||
297 | static int zlib_decompress_final(struct crypto_pcomp *tfm, | |
298 | struct comp_request *req) | |
299 | { | |
300 | int ret; | |
301 | struct zlib_ctx *dctx = crypto_tfm_ctx(crypto_pcomp_tfm(tfm)); | |
302 | struct z_stream_s *stream = &dctx->decomp_stream; | |
303 | ||
304 | pr_debug("avail_in %u, avail_out %u\n", req->avail_in, req->avail_out); | |
305 | stream->next_in = req->next_in; | |
306 | stream->avail_in = req->avail_in; | |
307 | stream->next_out = req->next_out; | |
308 | stream->avail_out = req->avail_out; | |
309 | ||
310 | if (dctx->decomp_windowBits < 0) { | |
311 | ret = zlib_inflate(stream, Z_SYNC_FLUSH); | |
312 | /* | |
313 | * Work around a bug in zlib, which sometimes wants to taste an | |
314 | * extra byte when being used in the (undocumented) raw deflate | |
315 | * mode. (From USAGI). | |
316 | */ | |
317 | if (ret == Z_OK && !stream->avail_in && stream->avail_out) { | |
318 | const void *saved_next_in = stream->next_in; | |
319 | u8 zerostuff = 0; | |
320 | ||
321 | stream->next_in = &zerostuff; | |
322 | stream->avail_in = 1; | |
323 | ret = zlib_inflate(stream, Z_FINISH); | |
324 | stream->next_in = saved_next_in; | |
325 | stream->avail_in = 0; | |
326 | } | |
327 | } else | |
328 | ret = zlib_inflate(stream, Z_FINISH); | |
329 | if (ret != Z_STREAM_END) { | |
330 | pr_debug("zlib_inflate failed %d\n", ret); | |
331 | return -EINVAL; | |
332 | } | |
333 | ||
334 | ret = req->avail_out - stream->avail_out; | |
335 | pr_debug("avail_in %u, avail_out %u (consumed %u, produced %u)\n", | |
336 | stream->avail_in, stream->avail_out, | |
337 | req->avail_in - stream->avail_in, ret); | |
338 | req->next_in = stream->next_in; | |
339 | req->avail_in = stream->avail_in; | |
340 | req->next_out = stream->next_out; | |
341 | req->avail_out = stream->avail_out; | |
342 | return ret; | |
343 | } | |
344 | ||
345 | ||
346 | static struct pcomp_alg zlib_alg = { | |
347 | .compress_setup = zlib_compress_setup, | |
348 | .compress_init = zlib_compress_init, | |
349 | .compress_update = zlib_compress_update, | |
350 | .compress_final = zlib_compress_final, | |
351 | .decompress_setup = zlib_decompress_setup, | |
352 | .decompress_init = zlib_decompress_init, | |
353 | .decompress_update = zlib_decompress_update, | |
354 | .decompress_final = zlib_decompress_final, | |
355 | ||
356 | .base = { | |
357 | .cra_name = "zlib", | |
358 | .cra_flags = CRYPTO_ALG_TYPE_PCOMPRESS, | |
359 | .cra_ctxsize = sizeof(struct zlib_ctx), | |
360 | .cra_module = THIS_MODULE, | |
361 | .cra_init = zlib_init, | |
362 | .cra_exit = zlib_exit, | |
363 | } | |
364 | }; | |
365 | ||
366 | static int __init zlib_mod_init(void) | |
367 | { | |
368 | return crypto_register_pcomp(&zlib_alg); | |
369 | } | |
370 | ||
371 | static void __exit zlib_mod_fini(void) | |
372 | { | |
373 | crypto_unregister_pcomp(&zlib_alg); | |
374 | } | |
375 | ||
376 | module_init(zlib_mod_init); | |
377 | module_exit(zlib_mod_fini); | |
378 | ||
379 | MODULE_LICENSE("GPL"); | |
380 | MODULE_DESCRIPTION("Zlib Compression Algorithm"); | |
381 | MODULE_AUTHOR("Sony Corporation"); |